B 3 341 01

ALVMNVS BOOK FVND

BIOLOGY
RA
G

A NOTE BOOK

FOR

PRACTICAL BIOLOGY

BIOLOGICAL LABORATORY

CAMBRIDGE

*1

1914

[All rights reserveif]

C3

BIOLOGY

LIBRARY

G

PRINTED BY JOHN CLAY, M.A.
AT THE UNIVERSITY PRESS

1C.

CONTENTS

RANA

HISTOLOGY

AMCEBA

PARAMECIUM

VORTICELLA

HYDRA

LUMBRICUS

ASTACUS .

SCYLLIUM .
DOG'S SKULL

PAGE

I

14

20

21
22
23
25
31
36
48

RABBIT

THE PLANT CELL

COLOURLESS PLANT-CELLS

BACTERIA .

FUNGI

ALG.E

LIVERWORTS

MOSSES

FLOWERING PLANTS

49
65
66
67
68
70

75
76

77

681389

1

RANA

i. Lateral view of the Frog: head; trunk; fore-limbs; hind-limbs; sacral prominence; mouth; external
nares ; eye ; tympanic membrane ; cloaca ; bristle passed through the tympanic membrane, a,n,d traced into the
mouth by the Eustachian tube; bristle passed into the external nares and traced into tta;m"3u;th\by the; \ttitBrnal
nostril. >'"' > • ».»,, ,,. , ...

^

2. Enlarged drawings of the palmar surface of the fore-foot, or manus, with four digits (numbered 2—5;,
the praeaxial (internal) digit with pad in the male ; and of the plantar surface of the hind-foot, or pes, with five
digits (numbered), webbed.

' ••*. *

2 RANA

3. View of mouth widely opened : maxillary teeth ; vomerine teeth ; posterior nares ; eyeballs ; Eustachian
tubes ; tongue ; glottis.

-*?> Wh^-t UJL

6

4. Ventral view of the same frog firmly pinned by its legs ; the integument has been reflected from the body
and throat ; anterior abdominal vein seen through the muscular wall ; musculo-cutaneous veins ; xiphoid
cartilage ; hypoglossal nerve ; mylohvoid muscle.

ft/01

VT

a

^

Y/i) <'

u/

rl. '

y£ j.. ^ani

kd*

-

3 RANA

5. View of the ventral aspect of same frog, in which the muscular wall of the abdomen has been opened
by a longitudinal cut a little to the left of the middle line so as to avoid the anterior abdominal vein ; the pectoral
girdle has been cut through a little to the left of the middle line ; the cut abdominal and pectoral walls are pinned
back on either side, and the anterior abdominal vein is doubly ligatured near where it enters the liver with thread^

Heart ; liver ;

and djtfidecl between the ligatures. The viscepa are displaced so as to shew as much as possible.
gall-bladder ; lung ; stomach ; spleen ; duodenum and pancreas ; hepato-pancreatic duct ; intestine ;
or ovaries ; fat-bodies ; oviducts (in female) ; cloacal bladder.

rectum; testes

4 RANA

6. View of the urinary and generative organs of a male from the ventral side.^/ (The alimentary canal has
been removed by cutting through the oesophagus, mesentery and rectum.) Fat-bodies; testes; vasa efferentia;
kidneys; renal portal, femoral, sciatic, pelvic, anterior abdominal veins; urinogenital duct; vesicula seminalis;
inferior vena cava; cloacal bladder.

7. View of same parts in female : ovaries ; oviduct ; internal opening of oviduct ; ureter ; the other organs
and veins as in 6. .

o vr*

, ^.. *•**•*

YUM)

5 RANA

Open the abdominal cavity and expose the heart by cutting through the pectoral girdle as in 5.

8. View of the great venous trunks converging to the heart. Remove the pericardium, draw the ventricle
forward so as to expose the dorsal side of the heart, and cut through the ligament connecting the base of the
ventricle to the dorsal wall of the pericardia! cavity. Heart ; sinus venosus ; inferior vena cava ; superior vence
cavce ; external jugular, innominate, internal iugufar, subscapular, subclavian, musculo-cutaneous, brachial veins.
Note also the pulmo-cutaneous veins opening into\the left auricle, and the hepatic veins opening into the
inferior vena cava. /

6

RANA

9. View of the heart and arterial arches, after removing the external jugular vein. Ventricle; auricle;
conus arteriosus ; carotid 'arch ; systemic arch ; pulmo-cutaneous arch ; lineal artery ; carotid gland ; common
carotid artery ; dorsal aorta ; subclavian artery ; cceliaco-mesenteric artery ; iliac artery.

Yuuri >

10. Plan (on opposite page) of the. venous system of the Frog as determined by the preceding dissections:
sinus venosus; superior vence cava; inferior vena cava; hepatic, hepatic-portal, gastric, mesenteric, renal,
genital, renal portal, femoral, sciatic, pelvic, anterior abdominal veins.

7 RANA

ii. Open the abdominal cavity and expose the heart by cutting through the pectoral girdle.
Heart; glossopharyngeal nerve (cranial ix) ; vagus (cranial x) ; hypoglossal nerve (spinal i) ; internal jugular
vein', brachial nerve. — (Trace the vagus to the heart)

12. View of the hinder part of the body-cavity of the same frog from which the kidneys and generative
organs have been removed without injuring the aorta : vertebral column ; dorsal aorta; iliac arteries ; calcareous
concretions; spinal nerves; sympathetic ganglia; rami communicantes.

~~

8

RANA

13. Central nervous system seen from above, as exposed by removing the roof of the skull and the neural
arches : olfactory lobes (fused) ; cerebral hemispheres ; thalamencephalon ; optic lobes ; cerebellum ; medulla oblongata ;
fourth ventricle ; spinal cord ; dorsal fissure of spinal cord.

14. The same removed from the body and seen with its ventral side uppermost : olfactory lobes ; cerebral
hemispheres ; optic chiasma ; infundibulum ; pituitary body ; crura cerebri ; ventral fissure of spinal cord.

&feUt4*M.4<

9

RANA

15. Vertebral column and pelvic girdle, dorsal aspect: eight prasacral vertebra; sacral vertebra; inter-
vertebral notches for the outlet of nine of the ten pairs of spinal nerves ; urostyle ; ilium ; acetabulum ; ischium.

vy&2/#vi*c<v>_-_.

10

RANA

16. Skull viewed from above: premaxilla; maxilla; nasal; sphenethmoid ; fronto-parietal ; otic; pterygoid;
squamosal; quadrato-jugal ; exoccipital; orbital fossa.

17. The same viewed from below : premaxilla ; maxilla ; vomer ; parasphenoid ; palatine ; sphenethmoid ;
pterygoid; quadrato-jugal; otic; exoccipital; foramina of the optic (n), trigeminal (v), glosso-pharyngeal (ix),
and vagus (x) nerves.

RANA

18. Hyoid cartilage : basi-hyal : anterior cornua ; posterior cornua.

0

19. Pectoral girdle and "sternum," ventral view: suprascapula ; scapula; glenoid cavity; preecoracoid,
covered by clavicle ; coracoid ; coracoid foramen ; episternum ; omosternum ; xiphisternum ; xiphoid cartilage.

12 RANA

20. Fore-limb: humerus; radio-ulna; carpus; metacarpus; phalanges; four digits (2 — 5).

21. Hind limb: Jemur; tibio-fibula; tarsus with elongated calcaneum and astragalus; metatarsus; five
digits ; calcar.

e> ft

13

22. Stages in the development : eggs ; tadpoles ; etc.

•

RANA

14 HISTOLOGY

1. Frog's Blood. Take a drop of the blood on a coverslip diluting with a drop of normal salt solution
(75 %)• Place on a slide and examine under the high power of the microscope. Draw the red corpuscles
shewn in full face and in side view. Move the slide about to find white corpuscles (leucocytes).

Place a drop of acetic acid (i %) at one side of the coverslip and allow it to diffuse under. Observe the
nuclei.

Make a film by thinly smearing one side of a coverslip with blood, and dropping it into absolute alcohol.
Place for 3 — 4 minutes in methylene blue and examine under the high power. Observe the red blood corpuscles
with nuclei clearly stained. Also the leucocytes, some hyaline and others with deeply stained granules.

2. Mammalian Blood. Draw a drop of blood from the finger with a clean needle and dilute with normal
salt solution as before. Observe the red corpuscles, shewn in full face, in side view, and in rouleaux. Search
for white corpuscles. Irrigate as before with acetic acid (i %) and observe that the latter alone are nucleated.

• •

3. White Fibrous Tissue. Pull up with fine forceps the thin connective tissue between the muscles of
the frog's thigh and cut off a small piece with scissors. Spread out on a dry slide with needles, and carefully
place over it a dry coverslip, allowing a drop of normal salt solution to diffuse under. Examine under the high
power of the microscope. Observe the wavy bundles of fibrillce crossing each other in every direction, and
the connective tissue cells, which will be made clearer by irrigating with acetic acid (i %), while the fibrillae will
disappear.

15 HISTOLOGY

4. Tendon. Place on a slide a small piece of thin tendon from the end of one of the leg muscles of the
frog. Keep moist by normal salt solution. Hold one end in position with a needle and fray out the fibres
at the other end by passing a needle along them. Cover and examine fresh. Observe the white fibres in parallel
bundles with tendon cells jn rows between them. Irrigate with acetic acid (i %) and observe the nuclei of the
tendon cells. Notice that the fibres swell up into a gelatinous mass.

5. Pigment cells. Take a piece of the web between the toes of a frog and spread it out on a slide. Observe
under the high power the pigment cells, some with numerous branched processes, others rounded, their processes
having been retracted.

16 HISTOLOGY

6. Adipose Tissue. Take a piece of the mesentery of the rat and spread it out on a slide, mounting in
normal salt solution. Observe the spherical highly refractive fat-cells. Irrigate with a drop of osmic acid and
observe after half-an-hour that the fat has been stained black.

7. Hyaline Cartilage. Strip off the free edges of any of the thin cartilages of the sternum of a frog.
Mount in normal salt solution and examine. Observe the cells lying in a matrix of collagen. Irrigate with
acetic acid (i %) and notice that the cells are more distinct and that their nuclei are now visible.

' fa-

17 HISTOLOGY

8. Muscle Striated. Cut through the skin covering the thorax, and remove one of the strands of tissue
connecting the " sternum " with the skin. Lay it on a slide and tease out thoroughly. Crush some of the fibres
by pressing a bristle across them. Place on coverslip and let a drop of normal salt solution pass underneath.
Observe the muscle sheath of the fibres at the crushed spot and the alternate dim and light bands. Irrigate
with acetic acid (i %) and observe the scattered oval nuclei.

*• '. • •

'v Hi"

I/

9. Muscle Unstriated. Take a piece of the bladder of a frog and spread its outer surface on a slide
allowing its edges to dry and fix themselves to the glass. Rub off the internal epithelium with the finger.
Put on one drop of 90 % alcohol and then one drop of eosin and methylene blue. Examine under the high
power and observe the unstriated muscle fibres arranged in a plexus. Their nuclei are stained. Note also the
connective tissue cells with stained nuclei.

18 HISTOLOGY

10. Sciatic Nerve. Cut out a quarter of an inch of the sciatic nerve of the frog. Hold one end on a slide
by the blunt edge of a scalpel. Quickly tease out with a needle the other end into a fan. Add normal salt
solution and put on a coverslip. Observe the nerve fibres, which are of double contour on account of their fatty
sheath. At ends observe the transparent outer sheath of the fibres.

Place a drop of osmic acid on one side of the slide and draw it under the coverslip by absorbing the salt solution
by blotting paper on the opposite side : then remove the blotting paper to prevent the osmic acid being
absorbed. Leave for fifteen minutes and examine. Observe the nodes of Ranvier in the fatly sheath and the
nuclei halfway between two nodes.

u. Transverse Section of Sciatic Nerve prepared with osmic acid. Observe the grouping of the fibres
into bundles and the fatty sheaths as dark rings round the individual fibres.

19

HISTOLOGY

12. Transverse Section of the Small Intestine of a Frog. Observe that the cavity of the intestine
is lined by a single layer of columnar epithelial cells which are raised on folds of connective tissue. This is
abundantly supplied with blood vessels and lymph spaces, and is surrounded by a broad circular and a narrow
longitudinal layer of muscle fibres.

13. The same from a Frog fed with bacon. Observe that the epithelial cells are crowded with fat
granules.

14. Transverse Section of the Stomach of a Frog. Observe the much greater thickness of all the
layers as compared with the intestine. The epithelial cells instead of continuing as an even layer of cells over
the ridges form the gastric glands. These are a series of branched tubes, the epithelium of which secretes gastric
juice. Observe the subjacent connective tissue with blood vessels and the muscle layers.

20

AMCEBA

Sketches of the animal to shew changes of shape : pseudopodia ; ectoplasm ; endoplasm ; contractile vacuole ;
food vacuoles; nucleus.

Kill and stain with picrocarmine to bring out the nucleus. The introduction ot the staining fluid under the coverslip should
be effected by irrigation, i.e. by placing a drop of the fluid on the slide so that it just touches one side of the coverslip, and by
drawing out fluid from the opposite side by means of a piece of blotting paper. The staining fluid will then pass in to replace
the fluid taken up by the blotting paper. Care should be taken that there is always some fluid touching the coverslip, to replace
that taken out by the blotting paper.

21

PARAMECIUM

i. Sketches of the animal: cuticle; ectoplasm; cilia; trichocysts ; endoplasm; oral groove; gullet; food
vacuoles; macronucleus. Draw the two contractile vacuoles in systole and diastole.

V

&j£/jjf»"

2. Feed with Indian ink : food, vacuoles. Watch the entrance of the food pellets into the endoplasm, the
rotation of the food vacuoles, and the extrusion of their undigested contents by the temporary anus.

3. Stain with iodine: macronucleus; micronucleus ; trichocysts discharged.

22 VORTICELLA

Find under the low powei of the microscope. Sketch under the high powen

i. Enlarged drawing of the expanded body : epistome; peristome; cilia; oral groove; gullet; cuticle] ecto

plasm; endoplasm; contractile vacuole; food vacuoles; stalk; muscular fibre of stalk.

'

^ /t+mA&dAA

2. Stain with picrocarmme : nucleus.

3. Feed with Indian ink. Observe the process by which the small particles accumulate at the bottom ot
the gullet, pass into the endoplasm, form small round masses which circulate in food vacuoles and are finally
cast out into the oral groove through the temporary anus.

23

HYDRA

i. A view under hand lens of whole animal in watch glass: body; tentacles; foot; testes if present; ovary
if present; bud if present.

2. The same under low power, placing the watch glass on a slide to prevent rocking: oral cone; mouth;
tentacles. _ -di

3. Mount the animal alive on a slide, taking care that the coverslip does not press too heavily by placing
two slips of thin paper under it, and examine it first with a low power, then with a high. Draw portion of
tentacle under high power : ectoderm ; thread-cells arranged in batteries ; cnidocils ; endoderm seen through the
ectoderm.

24

HYDRA

4. Irrigate the animal with 5 per cent, solution of common salt and watch the protrusion of the filaments
of the nematocysts. Sketch detached nematocyst with the cnidoblast adhering to it.

5. Transverse section of the body ; draw with low power, fill in details of small portion with high : ectoderm ;
myo-epithelial cells ; interstitial cells ; nematocysts ; basement membrane ; endoderm ; vacuoles ; chloroplasts if
present; digestive cavity.

6. Longitudinal section of the body : parts as in 5.

25

LUMBRICUS

i. Dorsal view of the anterior part, enlarged: prostomium; peristomium ; clitellum from segment 32 to
37 inclusive; segments 2 to 40.

2. Ventral view: mouth; ventral setce; lateral setee; male genital pores (segment 15).

fit

© <«&/ ^*tA*fc

-••/

3. Extract a se^a with forceps. Mount and sketch under low power.

26

LUMBRICUS

4. Pin the animal, ventral surface downwards, by two pins through the clitellum and two through the sides
of the fourth segment. Stretch the body as much as possible. Open the body by a cut along the dorsal middle
line from segment 20 to segment 2 : fix the cut body-walls to the dissecting trough by pins on each side : septa ;
nephridia ; pharynx ; supra-pharyngeal ganglia ; oesophagus ; vesiculce seminales in segments 9 to 12 ; spermathecce
in segments 9 and 10 ; crop; gizzard; intestine; dorsal blood-vessel ; pseudo-hearts in segments 7 to n.

"•****>

27

LUMBRICUS

5. Anterior portion of the alimentary canal as seen when freed of surrounding structures in the following
manner : cut through intestine just behind gizzard ; lift up the gizzard with forceps and working forward separate
the alimentary canal from the septa; pin down the alimentary canal as thus reflected: pharynx; oesophagus;
cesophageal pouches (segment 10) ; cesophageal glands (segments n and 12); crop; gizzard; intestine. Look
for the ovaries in segment 13 as the dissection is carried forward.

28

LUMBRICUS

6. Nervous system, genitalia, and nephridia, as exposed when the alimentary canal, together with supra-
and sub-intestinal blood-vessels, has been reflected forward as in 5 : supra-pharyngeal ganglia (segment 3) ;
circum-pharyngeal commissure ; sub-pharyngeal ganglia (segment 4) ; ventral nerve cord ; spermathecce ; nephridia ;
anterior vesicula seminalis (segment 10) ; posterior vesicula seminalis (segment n) ; ovaries (segment 13).

29 LUMBRICUS

To make the observations under 7, 8, 9, 10 it will be necessary to use a worm which has been opened under
•75 per cent, (normal) salt solution.

7. Nephridium removed and seen under low power : nephrostome ; glandular part ; blood capillaries ; muscular
discharging part.

l\

8. Ovary under low power: immature ova; ripe ova.

9. Place a drop of the contents of a seminal vesicle on a coverslip and fix at once with 90 per cent, alcohol.
Wash gently with 70 per cent, alcohol, then with 50 per cent, alcohol. Place coverslip in watch glass containing
picrocarmine for 15 minutes. Wash in water and mount in dilute glycerine. Sketch various stages of development
of spermatozoa.

10. Treat a drop of the contents of a spermatheca as in 9. Sketch ripe spermatozoa.

\

30 LUMBRICUS

ii. Transverse section under low power, (i) Body-wall: cuticle; epidermis (ectoderm); circular and
longitudinal muscular layers. (2) Coelom. (3) Alimentary canal: typhlosole; yellow cells; muscular layers;
intestinal epithelium (endoderm).

Nerve cord ; dorsal blood vessel ; sub-intestinal blood vessel ; sub-neural blood vessel ; lateral setts ; ventral setce ;
nephridia.

• 'if* *

••'•/•' m^r -'"•

•<!S* -vVt*^

12. Longitudinal section of anterior end : prostomium; peristomium; mouth; pharynx; oesophagus; cssopha-
geal pouches and glands; anterior and posterior vesiculce seminales; supra-pharyngeal ganglia; sub-pharyngeal
ganglia; nerve cord; septa; other names as in u.

ASTACUS

i. Dorsal view: cephalo-thorax ; rostrum; cervical groove ; branchiostegite; abdominal terga; felson; uropod;
eye; antenmde; antenna; scale of antenna ; great chela; ambulatory limbs.

CrrtAX G
oc-»w» . — \. ^- t -TS -r / / — f 0

if a.

0

2. Fifth abdominal segment from behind : terguin; sternum; articulation of appendage ; biramous swimmeret.

\

-*vt- ,
'i.*i^t^t*

s.

32

ASTACUS

Remove all the appendages of one side from behind forwards, and pin them out on a sheet of paper. Sketch
as required below.

3. Third ambulatory limb. It is divided into seven Joints of which the basal carries a gill (podobranch) .

A

4. Mandible : toothed edge ; two jointed palp ; basal end ; tendon of muscle.

UUi

33

ASTACUS

5. Antenna: two-jointed basal portion; tubercle carrying orifice of the green gland; pointed scale; filament
of three large basal joints and a many-jointed continuation.

ff

f

T s&dt

6. Antennule: three-jointed basal portion; outer and inner many-jointed filaments.

7. Enlarged view of dorsal aspect of the basal joint of same : opening of statocyst. Cut open the joint to
see the statocyst, containing grains of sand.

'34

ASTACUS

8. Dorsal aspect of a crayfish from which the carapace and the abdominal terga have been removed : heart,
with two dorsal ostia ; testis or ovary ; stomach ; hepato-pancreas ; intestine ; muscle of the mandible ; great longi-
tudinal muscles.

In injected specimen: ophthalmic artery; antennary artery; gastric artery; dorsal abdominal artery.

't *-\

4^1

<&

•*• v A*

I

K

S
\

\

s

• T

AAHMAtALA

</ iX (X

9. Alimentary canal removed from body and seen from the side : oesophagus ; stomach ; mesenteron ; dorsal
ccecum ; hepato-pancreas ; rectum.

--

35

ASTACUS

10. The same crayfish with all its viscera removed except the green glands which lie right and left of the
mouth. The muscles of the tail and the false bottom of the thorax have also been removed. Supra-ossophageal
ganglia ; circum-cesophageal connectives ; six ventral ganglia of the cephalo-thomx ; sternal artery passing between
cephalo-thoracic ganglia 4 and 5 ; six ganglia of the abdomen ; green glands ; sacs of green glands.

36

SCYLLIUM

i. Side view: eye; mouth; spiracle; gill-clefts; lateral line; pectoral fins; pelvic fins; dorsal fins; anal fin;
caudal fin. Strip off a small portion of skin to shew the myomeres.

2. Ventral view : nasal apertures ; oronasal grooves ; mouth ; pectoral fin ; cloacal aperture ; pelvic fins, with
claspers in the male.

37

SCYLLIUM

3. Ventral view of contents of body cavity: falciform ligament; bilobed liver; position of gall bladder; bile
duct ; cardiac stomach ; pyloric stomach ; spleen; intestine- pancreas ; pancreatic duct', rectum ; , internal opening
of oviducts or vestige of same in male.

&cw^

4. Contents of body cavity from right side, as seen after turning the liver forward and drawing the stomach
downward : falciform ligament ; liver ; stomach ; intestine ; rectum ; rectal gland ; cceliac artery ; lieno-gastric
artery ; anterior mesenteric artery ; posterior mesenteric artery ; portal vein ; testis or ovary ; vas deferens or oviduct.

10

38

SCYLLIUM

5. Ventral view of heart and great vessels as exposed by a cut in the middle ventral line from the mouth
to the pericardium : sinus venosus ; auricle ; ventricle ; conus arteriosus ; hepatic sinus ; posterior cardinal sinus ;
anterior cardinal sinus; ductus Cuvieri; ventral aorta; afferent branchial vessels; thyroid gland; pericardio-
peritoneal opening; gill clefts and gills.

39 SCYLLIUM

6. The efferent branchial vessels, carotid arteries and anterior portion of the dorsal aorta, as seen after
cutting through the jaw and branchial arches on one side, turning the floor of the mouth outwards and removing
the mucous membrane from the roof of the mouth : efferent branchial vessels ; dorsal aorta ; subclavian artery ;
cceliac artery ; common carotid artery ; external carotid ; internal carotid ; gill clefts and gills.

40

SCYLLIUM

7. Dorsal view of orbit, as seen after cutting through the skin round the eye and pulling the eyeball out-
wards: eyeball; rectus externus; rectus intermis; rectus/ superior; obliquus superior; optic nerve (n) ; pathetic
nerve (iv).

8. Contents of orbit after removal of eye by cutting through the. six muscles and optic nerve close to the
eyeball: recti externus, internus, superior and inferior; obliqui superior and inferior ; optic nerve (n) ; oculo-motor
(in); pathetic (iv) ; main trunk of trigeminal (v), dividing into maxillary and mandibular branches; ophthalmic
branch ofv; hyomandibular , palatine and ophthalmic branches of facial (vn).

iftfff

^ \ f4W2*^y

* ^TCKjff:j
fa #

^^zUAhsAo,^

41

SCYLLIUM

g. Dorsal view of brain and spinal cord : olfactory lobes ; cerebrum ; thalamencephalon ; optic lobes ; cerebellum ;
medulla oblongata; restiform tracts; fourth ventricle; spinal cord; roots of cranial nerves n, in, iv, v, vn, vin,
ix and x; spinal nerves.

u

10. Glossopharyngeal (ix) and vagus (x) nerves as seen after slicing horizontally through the auditory capsule
until the nerves are exposed and then slitting open the anterior cardinal sinus : root of ix ; branches of ix to hyoid
and first branchial arches ; root of x ; branches of x to lateral line, to branchial arches i to 5, to heart and viscera ;
gill pouches.

tMbt

42

SCYLLIUM

ii. Ventral view of brain, removed from the skull: olfactory lobes; cerebrum; optic chiasma and nerves;
infundibiditm ; pituitary body; crura cerebri; medulla oblongata; restiform tracts; roots of cranial nerves in, v,
vi, vn, vin, ix and x.

^f A

^ </—*

JT rut^^

^IV* dJt

\W,^

43

12. Ventral view of kidney and generative organs after slitting open the cloaca.

SCYLLIUM

(a) Male : testis ; vasa efferentia ; vas deferens ; seminal vesicle ; sperm sac ; metanephros ; ureter ; cloaca ;
anus ; urino-genital papilla ; abdominal pouches ; pelvic fins.

(b) Female : ovary ; oviduct ; internal opening of oviduct ; shell gland ; cloacal opening of oviduct ; metanephros ;
cloaca ; amis ; urinary papilla ; abdominal pouches ; pelvic fins.

n

44

SCYLLIUM

13. Cranium, side view : ethmoidal region ; nasal capsules ; orbital region ; auditory capsule; occipital region;
foramina for optic (n), oculo-motor (m) , patheticus (iv), main branches of trigeminal (v) and facial (vn) and also
abducens (vi), ophthalmic branches of v and vn, glossopharyngeal (ix) and vagus (x) ; point of attachment of recti
muscles ; facet for hyomandibula.

14. Cranium, dorsal view: rostrum; nasal capsules; fontanelle; median ethmoid; aperture of auditory
meatus; auditory capsule.

\ c\-

7

•jbv- R!l*c6*/vC

j

45

SCYLLIUM

15. Cranium, ventral view : nasal capsules ; median ethmoid; groove for carotid artery ; foramina for external
carotid, internal carotid and nerves IX and x ; auditory capsules ; occipital condyles ; foramen magnum.

•Mb

16. Jaws and branchial arches, ventral view : palato-pterygo-quadrate bar ; lower jaw ; ethmopalatine ligament ;
hyomandibula ; ceratohyal ; basihyal ; ceratobranchials i — 5 ; basibranchials.

12

46

SCYLLIUM

17. Vertebral column, side view of trunk region : centrum ; neural arch ; neural spine ; intervertebral plate ;
transverse process; rib. /uJUUAJ**'

18. Vertebral column, side view of tail region : centrum ; neural arch ; neural spine ; intervertebral plate ;
haemal arch ; haemal spine.

19. Vertebral column, longitudinal section of part: centrum; notochord; neural spine.

47 SCYLLIUM

20. Pectoral girdle and fin : scapula; coracoid; glenoid facet ; propterygium ; mesopterygium ; metapterygium ;

bffrAarw

fin rays.

21. Pelvic girdle and fin: ischio-pubic part of girdle; iliac process; acetabular facet; basipterygium; fin
rays; clasper rod (in male only).

48

DOG

i. Skull, side view:

premaxilla ; nasal ; frontal ; parietal ; supra-occipital ; exoccipital ; occipital condyle ; maxilla ; orbit ;
lachrymal ; jugal ; palatine ; pterygoid ; alisphenoid ; squamosal ; tympanic ; external auditory meatus ; mandible ;
mandibular condyle ; coronoid process ; mandibular angle ; incisors | ; canines y ; premolars f ; molars §.

x - ^^u'uur-

2. Skull, ventral view:

premaxilla; maxilla; palatine; vomer; pterygoid; alisphenoid; basisphenoid ; basioccipital ; tympanic
bulla; exoccipital; occipital condyle; jugal; squamosal; glenoid fossa; incisors; canines; premolars; molars;
foramina for nerves; foramen magnum.

49

RABBIT

1. Second lumbar vertebra:

(a) front view: anterior epiphysis covering centrum; neural arch', neural canal; neurapophysis ; meta-
pophysis; transverse process; prezygapophysis ; hypapophysis.

(b) side view: centrum; postzygapophysis ; anapophysis; anterior epiphysis; posterior epiphysis; inter-
vertebral notch (for exit of spinal nerves). Other names as in (a).

2. Atlas (first cervical) vertebra, front view : transverse process ; prezygapophysis.

3. Axis (second cervical) vertebra, side view: odontoid process; neurapophysis.

.,

A

T*l

, it' '
J^/fl /^

rsf'

•

t^XVL <2-»<cX

4^-

^J^Lu^4

&

//- /

//

so RABBIT

4. Third cervical vertebra, front view : foramen for vertebral artery.

5. Third dorsal vertebra, side view: neurapophysis ; facet for tubercle of rib; facet for head of rib.

6. Sacrum, ventral view: surface of fusion with ilium.

7. Rib: head; tubercle; shaft.

8. Sternum with sternal ribs: manubrium; sternebrae; xiphoid cartilage; sternal ribs.

^

7

Y

V

51

RABBIT

9. Scapula, outer side: blade; dorsal border; anterior border; posterior border; spine; acromion; coracoid
process; glenoid cavity.

10. Humerus, hind view : head ; tuberosity ; trochlea ; olecranon fossa.

11. Radius and ulna: olecranon process of ulna.

12. Carpus, front view : radiate (scaphoid) ; intermedium (semilunar) ; ulnare (cuneiform) ; centrale; carpalei
(trapezium); carpale 2 (trapezoid) ; carpale 3 (os magnum); carpalia 4 and 5 (unciform).

13. Manus: digits I — 5; metacarpals; phalanges; pollex.

52 RABBIT

14. Pelvic girdle, outer side : ilium ; ischium ; pubis ; acetabulum ; obturator foramen.

15. Femur: head; great trochanter; lesser trochanter; third trochanter; condyles.

16. Tibia, fibula and patella: cnemial ridge of tibia.

17. Tarsus, front view : tibiale and intermedium fused (astragalus) ; fibulare (calcaneum) ; centrale (navicular) ;
tar sale 2 (mesocuneiform) ; tarsale 3 (ectocuneiform) ; tarsalia 4 and 5 (cuboid).

18. Pes: digits 2 — 5 (first digit or hallux is absent); metatarsals ; phalanges.

53

RABBIT

19. View of the abdominal viscera as seen when the animal is fixed on its back and the skin dissected from
the mu scular wall, which is opened by one median and one or more transverse cuts and then reflected : xiphoid
cartilage; liver; falciform ligament; stomach; small intestine; ccecum; colon; rectum; urinary bladder.

54 RABBIT

20. View of the stomach and commencement of the small intestine, as seen by turning up the liver and
spreading out the duodenum : oesophagus ; liver ; gall bladder ; bile duct ; portal vein ; cardiac region of stomach ;
pyloric region of stomach; pyloric sphincter; duodenum; pancreas; pancreatic duct; spleen.

55 RABBIT

21. View of abdominal viscera as seen after turning stomach and intestine to the animal's right side : kidney ;
suprarenal body ; dorsal aorta ; cceliac artery ; hepatic artery ; lienogastric artery ; anterior mesenteric artery ; renal
artery ; posterior mesenteric artery ; inferior vena cava ; left renal vein ; left vagus nerve on oesophagus ; solar
plexus; left splanchnic nerve.

56

RABBIT

22. Alimentary canal unravelled after removal from body in the following manner: the portal vein has
been ligatured in two places and cut between the ligatures, the oesophagus ligatured and cut above the ligature,
the rectum ligatured and cut below the ligature; the mesentery has been cut and the whole canal has been'
spread out on the dissecting board : oesophagus ; stomach ; pyloric sphincter ; small intestine ; sacculus rotundus ;
ccecum ; vermiform appendix ; colon ; rectum.

57

RABBIT

23. View of the abdominal cavity after removal of the alimentary canal : central tendon of diaphragm ;
muscular portion of diaphragm ; oesophagus ; kidneys ; suprarenal bodies ; ureters ; bladder ; dorsal aorta ; cceliac,
anterior mesenteric, renal, genital, posterior mesenteric and common iliac arteries : inferior vena cava ; renal, genital,
external iliac and internal iliac veins ; (a) in male : testis pulled out of scrotal sac ; epididymis ; vas deferens ;
uterus masculinus ; genital cord, ; (b) in female : ovaries ; oviducts ; internal openings of same ; uteri ; vagina ;
genital cord.

C)

58 RABBIT

24. Genital organs in side view after the symphysis pubis has been divided and one side of it removed:

(a) male : rectum ; bladder ; ureter ; vas deferens ; uterus masculinus ; urethra ; perineal gland.

(b) female: rectum; bladder; ureter; vagina; vestibule; perineal gland.

59

RABBIT

25. Thoracic organs as exposed by cutting through the ribs and removing the sternum : ribs ; thymus gland ;
heart; lungs; phrenic nerves; diaphragm.

26. The heart and great vessels as seen after the thymus gland has been removed and the heart turned
towards the animal's right side : left auricle ; left ventricle ; apex of heart ; pulmonary artery ; arch of aorta ;
innominate, right subclavian, right common carotid, left common carotid and left subclavian arteries ; aorta passing
through diaphragm ; left superior vena cava ; left subclavian, external jugular and pulmonary veins ; inferior vena
cava; oesophagus.

J

60 RABBIT

27. Vessels, nerves and other organs of neck and floor of mouth after removal of the skin and neck
muscles ; posterior cornua of hyoid bone ; larynx ; trachea ; thyroid gland ; oesophagus ; common carotid, external
carotid and internal carotid arteries ; external and internal jugular veins ; submaxillary gland ; main trunk of
vagus nerve; superior laryngeal, depressor, inferior (recurrent) laryngeal and hypoglossal nerves; cervical
sympathetic nerve ; superior cervical ganglion.

61 RABBIT

28. Heart and great vessels removed from the body, ventral view — the vessels should be cut through at
some little distance from the heart : apex ; left and right auricles ; left and right ventricles ; arch of aorta ;
pulmonary artery ; left and right superior vence caves ; pulmonary veins.

29. Dorsal view of same : names as in 28.

16

r

62 RABBIT

30. Head with skin removed, side view: external auditory meatus; masseter muscle; facial nerve; parotid
gland ; eyeball ; lachrymal gland ; infraorbital gland.

31. Mouth, view of interior as seen when opened widely after cutting through the muscles at its sides : upper
incisor teeth (4) ; upper premolar teeth (6) ; upper molar teeth (6) ; lower incisor teeth (z) ; lower premolar teeth (4) ;
lower molar teeth (6) ; ruga of hard palate ; soft palate ; posterior nares ; pharynx ; orifice of oesophagus ; glottis ;
epiglottis; tongue. After making the above sketch the soft palate should be slit open to expose the orifices of
the Eustachian tubes.

63 RABBIT

32. Brain removed from skull, dorsal view : olfactory lobes ; cerebral hemispheres ; cerebellum ; medulla
oblongata', fourth ventricle.

33. Brain as last, one cerebral hemisphere pulled outwards: corpus callosum; optic thalami; optic lobes.

34. Brain, ventral view : olfactory lobes ; temporal lobes ; optic chiasma ; optic nerve (n) ; Sylvian fissure ;
infundibulum ; pituitary body ; crura cerebri ; pans Varolii ; medulla oblongata ; in — xn roots of third to twelfth
cranial nerves.

64

35- Sheep's heart, interior of right side after exposure by a longitudinal cut through the ventral wall of
the right auricle and ventricle : wall of right auricle ; inter auricular septum ; fossa ovalis ; Eustachian valve ; wall
of right ventricle ; columnar carnece ; interventricular septum ; flaps of tricuspid valve ; chordce tendinece ; papillary
muscles; moderator band.

36. Sheep's heart, interior of left ventricle and root of aorta after exposure by a longitudinal cut through
the aorta and ventral wall of the left ventricle : wall of ventricle ; columnce carnece ; flaps of mitral valve ; chordce
tendinece ; papillary muscles ; semilunar valves of aorta ; orifices of coronary arteries.

[1]

65

THE PLANT CELL

Typical Cells of Plant.

i. Examine the fixed and stained section of the young growing portion of the root of the bean plant under
the high power. Find and draw (a) cubical cells with very thin cell-walls completely filled with protoplasm each
containing a large round nucleus shewing the deeply staining (chromatin) nuclear network, (b) oblong cells
in which a vacuole has appeared in the protoplasm, the nucleus remaining in a central position, (c) much longer
oblong cells in which the protoplasm forms a thin layer on the cell-wall : in this layer the nucleus is enclosed,
bulging out the protoplasm into the vacuole, which now fills the whole of the centre of the cell, occupying much
the greater portion of its volume.

n;»

2. Mount a leaf of Elodea in water. Examine under a low power and note that the leaf consists of
numerous cells. Sketch a single cell under the high power, shewing the cell-wall, protoplasm, chloroplasts,
nucleus, and vacuole. The nucleus is often somewhat difficult to find.

Movement of plant protoplasm.

Observe the circulation of the protoplasm especially in the cells along the middle of the under surface of the
leaf. The green chloroplasts are carried round and round the cell by this circulation. Indicate in your sketch
the course of the circulation by means of arrows.

T:

[1] 66 COLOURLESS PLANT-CELLS

Yeast (Saccharomyces Cerevisice).

A. Yeast cell under high power, shewing the cell-wall, the protoplasm, and the vacuoles. Run in iodine
solution ; the protoplasm and cell-wall are stained brown, and are seen more clearly.

[NOTE. — In the yeast cell the large central vacuole is contained within the nucleus, most of the chromatin of
which is situated at one end of the vacuole and closely applied to it. These relations, which are quite exceptional
in plant -cells, cannot be clearly seen except in stained specimens prepared by special methods.]

B. Yeast cells in different stages of budding. .

[1] 67 BACTERIA

A . Bacteria in pea extract. Mount a drop of the turbid liquid (pea infusion that has been exposed to
air for a fortnight), put on a coverslip and observe the numerous bacteria in motion. The preparation must be
very carefully focussed with the high power.

B. Bacteria in air. Remove the cover from the dish of sterilised gelatine provided, thus allowing the
dust of the air to settle on it. Replace the cover after an hour and label the dish with your name. After a week
or two the number of bacterial and fungal colonies arising from the bacterial and fungal spores deposited from
the air can be counted.

C. Bacillus subtilis. Examine the stained preparation provided. Notice and draw the abundant rod-
shaped bacteria. Compare their size with that of a yeast cell.

D. Examine the stained slides of various pathogenic (disease) bacteria shewing different bacterial forms,
spore formation, etc.

o

[21

68

FUNGI

White Mould (Mucor).

A. Mount a small piece of young Mucor (grown on gelatine) in water. Sketch a portion of a young hypha,
shewing the cell-wall and the protoplasm containing numerous vacuoles, which are smaller towards the growing
tip of the hypha.

B. An older mycelium of Mucor growing in gelatine. Place the watch-glass containing the gelatine and
the fungus on the stage of the microscope, and examine under a low power, noting sporangia.

C. Draw young sporangia, some shewing spores, and some in an earlier stage of development, seen under
high power.

D. Examine the still older Mucor growing on bread and sketch a sporangium which has burst, shewing
(a) the columella, to which some spores may be found adhering, (b) the collar or remains of the sporangium wall
at the base of the columella.

E. Examine the slide shewing conjugating hyphae and developing zygotes.

r

C

[2]

69

FUNGI

Blue Mould (Penicillium).

Examine the blue mould under the low power in air. Note the brushes of radiating conidiophores rising erect
from the mycelium (vegetative body of the plant). Now remove a small piece of the mould, place it in a
watch-glass of spirit and transfer to a drop of dilute glycerine on a slide. Put on a coverslip, and examine the
septate hyphae ; also the conidiophores and note the row of spores (conidia) cut off from the end of each
branch.

Types of Higher Fungi.

Examine the demonstration specimens of higher fungi parasitic on leaves, etc. ; also the mushroom (fruit
body of a fungus living in richly manured soil).

18

c

[3]

70

ALOffl

Pleurococcus.

A. Remove a small quantity of the green powder from the piece of bark provided, and mount in a drop
of water. Examine under a high power and sketch a single Pleurococcus cell, shewing the cell-wall and the chloro-
plast which occupies most of the cell cavity, often appearing completely to fill it. Look for cells in which colourless
protoplasm can be seen at one side of the cell. The nucleus can rarely be distinguished.

B. Mount some of the Pleurococcus from the watch-glass of water and draw groups of cells illustrating
different stages of division.

'

K

/ (

[3] 71 ALG5J

Spirogyra.

A . Make a diagrammatic sketch of part of a filament under a low power, shewing the single row of similar
cells, containing the green spiral chloroplasts.

B. Treat a fresh specimen with 5 % salt solution (by drawing a drop under the coverslip with blotting-
paper) and observe the shrinking of the protoplasmic lining. This phenomenon is known as plasmolysis. Sketch
a contracted cell. Draw water through with blotting-paper and observe the cell reassume its turgid condition.

C. Mount the two preserved filaments of Spirogyra provided and stain with iodine. One has been fixed
after illumination and contains much starch, the other, kept for two days in the dark, contains no starch.

D. Sketch a single cell under a high power shewing

(a) the cell-wall ;

(b) the spirally wound chloroplast with the pyrenoids, each of which is surrounded by starch-grains. Run
in iodine (by drawing a drop under the coverslip with blotting-paper) and notice that the starch surrounding the
pyrenoids is stained dark blue ;

(c) the thin layer of colourless protoplasm closely pressed against the cell-wall ;

(d) the nucleus suspended by strands of protoplasm ;

(e) the large vacuole containing cell-sap.

[Staining with iodine or with eosin may be necessary for d.]

A.

e

[3] 72 ALGrJE

Spirogyra (continued).

E. Conjugating cells of Spirogyra filaments. Examine the slides of red-stained material provided and select
examples, from which to draw (a) the lateral protuberances of cells in an early stage of conjugation, (b) meeting
of protuberances, (c) passage of protoplasm through conjugation canal, (d) young zygote, (e) older zygote with
thick wall. Draw as many distinct stages as you can distinguish.

(N.B. In some forms of Spirogyra conjugation takes place between adjacent cells of the same filament.)

' I

C=i

rH

[4] 73 ALGrlE

Bladder-wrack (Fucus).

A. Make a drawing of the thallns shewing the forked branching, the attachment, and the swollen ends of
the branches bearing conceptades.

B. Examine a transverse section of the thallus. Draw (a) the closely packed assimilating cells with phceoplasts
on the surface, (b) the thin-walled conducting cells in transverse section, (c) the thick-walled fibres in transverse
section.

[4] 74 ALG.ffi

Bladder-wrack (Fucus) continued.

C. Examine a longitudinal section of the stalk of the thallus. Draw (a) the surface layer of square or oblong
cells with brown phaeoplasts, (b) the longitudinally running conducting cells with abundant contents and perforated
cross walls, and (c) the longitudinally running thick-walled fibres.

D. Examine a transverse section through the reproductive part of the thallus. Note the assimilating cells
on the surface and the loose tangle of conducting cells in the centre. Draw a conceptacle containing (a) oogonia,
with eight egg-cells when ripe, (b) the antheridial branches, bearing the long oval antheridia with dense contents,
(c) the sterile hairs.

E. In fresh material notice the antherozoids (sperms) and egg-cells (ova) extruded from the mouth of the
conceptacle. Mount some of these in sea-water and observe the movements of the sperms.

[5] 75 LIVERWORTS

Pellia.

A. Examine a plant of Pellia (a common Liverwort). Sketch the form of the flat green branching thallus,
with a thickened midrib attached by rhizoids to the soil.

B. Draw a transverse section through the thallus, shewing the uniform parenchymatous thin-walled tissue,
containing numerous chloroplasts, especially towards the upper surface, and starch grains ; also rhizoids arising
from the lower surface and penetrating the soil.

C. Examine and draw a section through the spore capsule shewing capsule wall, spores and elatcrs.

D. Examine a ripe spore-capsule. Note the four valves into which the capsule splits. Examine some of
the brown spores in dilute glycerine under the high power.

[5] 76 MOSSES

Funaria.

A. Examine a single plant of Funaria (a common Moss) under the dissecting microscope. Make a sketch
illustrating the differentiation of the plant -body into (a) a slender axis, bearing (b) delicate green leaves, and
(c) brown rhizoids in a tuft on the lower part of the axis. The leafy axis bears a slender stalk terminating in
a pear-shaped capsule containing spores similar to the spores of Pellia.

B. Detach a single leaf and examine it in water under a low power. Observe that it consists of a single
layer of cells all alike and that there are no veins. Under the high power draw some of the cells shewing
the thin cell-wall, protoplasm with numerous disc-shaped chloroplasts embedded in it and the large vacuole
occupying most of the cell-cavity, as in Elodea.

C. Examine some of the brown rhizoids under the high power and observe that they consist of threads of
cells, branching at intervals. The end walls of the cells are very oblique.

D. Examine the transverse section of the stem of Mnium (another common Moss). Distinguish in a
drawing the narrow thin-walled water-conducting cells, the larger cortical cells and the thick-walled protective
r.ells on the surface.

ILA

[6] 77 FLOWERING PLANTS

Vegetative organs.

ARRANGEMENT OF LEAVES, STEMS AND ROOTS IN DIFFERENT TYPES
I. Erect herbaceous plant.

A. Examine the upright herbaceous plant. Make a sketch shewing the relations of the following parts:
tap-root, branch roots, hypocotyl, cotyledons, nodes, internodes, leaves, leaf-veins, axillary buds, and terminal buds.

i.0

[6]

78

FLOWERING PLANTS

Vegetative organs (continued}.

ARRANGEMENT OF LEAVES, STEMS AND ROOTS IN DIFFERENT TYPES
II. Rhizome.

B. Examine the creeping underground stem of Solomon's Seal (Polygonatum). The main stem is a
horizontal rhizome remaining below the ground, bearing leaf scales at its nodes, and adventitious roots.

The apical bud of this rhizome turns vertically upwards and grows out into the leafy flowering shoot.
This dies down in the autumn and the plant remains below ground with food stored in the fleshy rhizome.

Growth is continued by a bud arising in the axil of a scale leaf on the rhizome.

[6] 79 FLOWERING PLANTS

Vegetative organs (continued).

ARRANGEMENT OF LEAVES, STEMS AND ROOTS IN DIFFERENT TYPES
III. Tuber.

C. Make a sketch of the tuberously thickened underground stem of the Chinese artichoke (Stachys tuberifera),
marking nodes, scales, axillary buds, internodes, upwardly turned terminal bud.

D. Jerusalem artichoke (Helianthus tuberosus). Sketch the tuber as seen from the side, marking scales,
axillary buds, and terminal bud.

E. Sketch the sprouting potato (Solanum tuberosum} : shewing tuber, leafy shoots, and adventitious roots
arising from their base.

-.»<*'

[6] so FLOWERING PLANTS

Vegetative organs (continued).

ARRANGEMENT OF LEAVES, STEMS AND ROOTS IN DIFFERENT TYPES
IV. Corm.

F. Crocus corm (autumn — resting stage). Cut the corm longitudinally through the middle and sketch
the section, marking scar left by falling off of flowering shoot, protective scales, buds in their axils, which will form
new flowering shoots.

G. Crocus plant (spring stage). The buds in F have grown out into flowering shoots, whose bases are
thickening to form new corms.

Identify the scar of last year's flowering shoot.

ner*

J-— \x***^

_><*<#

[6]

81

FLOWERING PLANTS

Vegetative organs (continued).

ARRANGEMENT OF LEAVES, STEMS AND ROOTS IN DIFFERENT TYPES

V Bulb.

H. Tulip bulb (autumn — resting stage). Cut through the middle of the bulb longitudinally and make
a drawing of the section, marking protective scales, bulb scales, and terminal bud. Look for axillary bud which
will form next year's bulb.

I. Tulip plant (spring stage). The terminal bud in H has grown out into the flowering shoot. Cut through
the old bulb longitudinally and draw the section, shewing the new bulb arisen from an axillary bud formed in
the autumn, roots, etc.

21

f I

'£•<>**

* •- I 0 f

[7]

82

FLOWERING PLANTS

Leaves.

A . Examine the transverse section of the leaf-lamina provided. Make a drawing of the structure, shewing
(a) the epidermis and cuticle of the upper surface, (b) the palisade cells of the mesophyll, (c) the spongy tissue of
the mesophyll with large intercellular air-spaces, (d) the lower epidermis, its stomata and cuticle. Note also (e) the
vascular bundles.

B. Mount another section in Schulze's solution. Note that the cuticle turns yellow while the cellulose-walls
and starch grains turn blue.

C. Examine the leaf of geranium (Pelargonium) in the glass of coloured solution. Cut across the leaf-stalk
and veins and observe that the coloured solution has been sucked up in the wood elements of the vascular bundles.

D. Strip off a piece of the epidermis from the lower surface of a leaf of Iris ; mount it in water and sketch
under a high power (a) a few of the epidermal cells, without chloroplasts, and (b) the guard cells, containing
chloroplasts, surrounding the pore of each stoma. Treat the upper epidermis similarly and note that stomata
are absent.

E. Examine a transverse section of the leaf of Iris, and draw a vascular bundle, distinguishing (a) xylem
with tracheids, (b) phloem with sieve-tubes and companion-cells, (c) hard bast of fibres. Stain with analine
chloride. This turns lignified tissues bright yellow.

Examine also and draw a stoma in transverse section distinguishing (a) guard-cells with cell cavities containing
chloroplasts, (b) cuticle of guard-cells and neighbouring epidermal cells, (c) vestibule, (d) pore of stoma.

[7] 83 FLOWERING PLANTS

Leaves (continued).

F. Place the lamina of a fresh leaf (e.g. Limnocharis) in water, then suck the end of the leaf-stalk and note
the dark patches that appear on the leaf-blade. These are due to water having been sucked through the stomata
into the intercellular spaces.

G. Examine the shoots of Gorse (Ulex). Make a diagrammatic sketch to shew the arrangement of " leaf-
spines " and " stem-spines."

[8]

84

FLOWERING PLANTS

Roots.

A . Draw a single mustard seedling under the dissecting microscope to shew the numerous root-hairs. Notice
that the hairs are shorter towards the root apex.

B. Mount the root of the seedling in water, and flatten it out under a coverslip. Draw some root-hairs
to illustrate their origin from single superficial cells.

C. Examine the fresh Bean root, observe the root-cap at the growing point and the four or more longitudinal
rows of lateral roots. Cut the root across and make out with a lens the endogenous origin of the lateral roots.

D. Separate the cortex of the root from the stele by twisting the root to break the cortex and pulling it off
like a sheath.

[8] 85 FLOWERING PLANTS

Roots (continued).

E. Make a drawing of a transverse section of the stele of the root of a Buttercup. Shew the well-marked
endodermis, the pericycle, and the four alternating xylem and phloem strands.

F. Examine the transverse section of young bean root, noting especially the piliferous layer with root-hairs

G. Draw the longitudinal section through the apex of a root (Maize) shewing (a) the growing point, (b) root-
cap, (c) young stele.

22

[9]

86

FLOWERING PLANTS

Herbaceous Stems.

A . Draw the piece of stem provided which bears leaves and axillary buds at the node. Note the arrangement
of the vascular bundles in the cut stem and cut leaf-stalk.

B. Dissect the growing-point of the stem and sketch the rudimentary leaves of a Brussels sprout.

C. Make a diagram of the growing region of the stem of the Brussels sprout as seen in longitudinal section,
shewing (a) growing-point (primary meristem), (b) the youngest leaves, (c) older leaves with buds in their axils,
(d) young vascular bundles.

[9] 87 FLOWERING PLANTS

Herbaceous Stems (continued).

D. Examine in water, a transverse section of the stem of the Sunflower and draw a diagram indicating the
following tissues and system of tissues ; epidermis, outer cortex, inner cortex, endodermis (starch sheath) and
central cylinder (stele) consisting of (i) pericycle (fibrous opposite bundles, parenchymatous between), rays, pith,
and (ii) vascular bundles, shewing xylem, phloem and cambium.

Add a drop of Schulze's solution, and observe that the cell-walls of most of the tissues turn blue (cellulose)
while those of the pericycle fibres and most of the xylem turn yellow (lignified).

[9]

88

FLOWERING PLANTS

Herbaceous Stems (continued).

E. From the stained section provided make a careful high-power drawing of a few cells of each of the following
tissues : (a) epidermis with cuticle ; (b) outer cortex consisting of thick-walled cells (collenchyma) ; (c) inner
parenchymatous cortex; (d) endodermis; (e) pericycle fibres; (/) phloem, including sieve-tubes, companion-
cells and parenchyma ; (g) cambium ; (h) xylem, including large (pitted) vessels, xylem fibres, parenchyma,
and (i) protoxylem ; (j) cells of the medullary rays which are beginning to form the interfascicular cambium.

F. Examine the radial longitudinal section and draw under the high power a few cells of each of the following
tissues : (a) phloem shewing sieve-tubes and companion-cells ; (b) metaxylem shewing part of a pitted vessel, some
adjoining parenchyma and fibres, and (c) protoxylem shewing spiral vessels and adjoining thin-walled parenchyma.

n

[10] 89 FLOWERING PLANTS

Woody (Arboreal) Stems.

A . Draw a winter branch of Horse-chestnut shewing several years' growth. Mark terminal buds, lateral
buds, covered with bud scales, leaf scars, bud-scale scars. Determine the age of the branch.

B. Make a diagram of the structure of the sprouting bud of Sycamore, shewing the arrangement of the
bud scales and foliage leaves. Draw scales which bear rudiments of a leaf-blade.

[10] 90 FLOWERING PLANTS

Woody (Arboreal) Stems (continued).

C. Examine the transverse section of a Maple branch three years old and draw a diagram shewing (i) the
cork ; (2) the outer cortex ; (3) the inner cortex ; (4) the pericyde ; (5) the secondary phloem ; (6) the cambium ;
(7) the secondary xylem with three annual rings ; (8) the principal secondary rays ; (9) the primary xylem, and
(10) the pith.

D. Examine the branch of Portugal Laurel that has been kept with its cut end in a coloured solution. Split
it longitudinally and note that the solution is carried up in the wood only.

CM.

[10] 91 FLOWERING PLANTS

Woody (Arboreal) Stems (continued).

E. Make a diagrammatic sketch of the different faces of the block of Oak, including : (i) the transverse
secticn shewing the annual rings, the large spring-vessels, which appear as small holes in the wood, the broad
medullary rays crossing the line of cambium, inner bark (yellow-brown) consisting of secondary phloem and outer
bark (red) with irregular bands of dark cork ; (ii) radial face, shewing the wood and broad medullary rays
(' silver grain ') ; (iii) tangential face, shewing the ends of the medullary rays as seen in the cut surface of
the wood.

Note on the transverse and radial faces the distinction between sapwood and heartwood.

[10] 92 FLOWERING PLANTS

Woody (Arboreal) Stems (continued).

F. Draw a portion of the outer tissues of a transverse section of the twig of Ailanthus under the high power
to shew the development of cork from the cork-cambium.

G. Examine the piece of willow branch provided. Observe the lenticels seen on its surface. Peel it and
note that the outer part separates at the line of the cambium.

[11] 93 FLOWERING PLANTS

Morphology of the Flower.
Buttercup (Ranunculus).

Sketch a single flower cut in half longitudinally exactly down the middle with a razor or very sharp knife,
shewing (a) receptacle, (b) calyx of sepals, (c) corolla of petals, (d) stamens, (e) carpels, (/) nectaries on the petals.

STAMENS.

A . Sketch under a lens, a single stamen shewing (a) the filament, (b) the anther with its two pairs of pollen-
sacs, (c) the connective or continuation of the filament between the pollen-sacs, and (d) the line of dehiscence of
the anthers.

B. Examine transverse section through a young anther and draw (a) the four pollen-sacs containing pollen-
grains, (b) the connective traversed by a vascular bundle, (c) the fibrous layer below the epidermis.

C. Draw also the section through a mature anther shewing the dehiscence.

•

[11]

94

FLOWERING PLANTS

Morphology of the Flower (continued).
CARPELS.

A. Remove a carpel from the old flower or young fruit of Caltha (Marsh marigold), draw the side view and
then split down the ovary to shew the many ovules inside, attached in two rows along the inner edge, corre-
sponding with the joined margins of the carpellary leaf.

B. Draw under a low power the transverse section of the ovary of Yucca provided, shewing the three joined
carpels, midrib and edges (placentae) of each, the ovules with (i) funicle and vascular bundle traversing it, (ii) inner
and outer coats, (iii) micropyle, (iv) nucellus, (v) embryo-sac.

C. Draw under a low power a diagram of the transverse section of the carpel of Aquilegia (Columbine) shewing
(i) midrib of carpellary leaf, (ii) edges (placentae) to which ovules are attached, (iii) cavity of ovary, (iv) ovules.

D. In the same section draw under the high power (a) the synergidae and the egg-cell, (b) the antipodal cells,
(c) the nucleus and vacuolated protoplasm of the embryo-sac, (d) the nucellus, (e) the coats of the ovule and if possible
indicate (/) the micropyle (very narrow and not traversed in most sections).

}

|A

[12]

Types of Flower.

95

FLOWERING PLANTS

I. CYTISUS. (Papilionata.)

A . A general sketch of the flower illustrating the form of a papilionaceous flower.

B. Dissect the flower and make sketches of (a) the calyx, (b) the corolla, consisting of five petals — the standard,
the two wings, the two coherent petals forming the keel, (c) the andrcecium, consisting of ten stamens, which are
joined together by their filaments. Slit open the staminal type to expose (d) the single carpel.; the basal swollen
part of pod is the ovary, the elongated portion the style ending in the stigma.

II. DOG DAISY (Chrysanthemum sp.). (Composites.)

A . Sketch the inflorescence of a Daisy cut in half, shewing (a) the receptacle, (b) involucre of bracts, (c) ray-
florets, (d) disc-florets.

B. Carefully remove and sketch a single ray-floret, shewing (a) ligulate corolla, (b) bifid stigma, (c) ovary.

C. Carefully remove a disc-floret (including the inferior ovary), and examine in water under the low power
of the microscope. Make a drawing shewing (a) tubular corolla with five lobes, (b) ovary, (c) anthers forming a
tube round the gynasceum, (d) the bifid stigma projecting beyond the anther-tube. Slit open a corolla, and make
a drawing of the free filaments of the five stamens, and the united anthers. Notice the arrangements for cross-
pollination.

\

[12] 96 FLOWERING PLANTS

Types of Flower (continued).

D. Make a sketch of a disc-floret of another Composite (e.g. Groundsel) to shew the pappus.

E. Mount a few pollen-grains from a fresh flower of Chrysanthemum in a drop of water ; examine under a
high power and sketch a single pollen-grain shewing the character of the outer coat.

F. Examine the preparation of sprouting pollen-grains shewing the formation of the pollen-tube.

G. Sketch the longitudinal section through a stigma [e.g. the Evening Primrose ((Enothera)] shewing the
pollen-grains and pollen-tubes in the tissue of the style.

,:

[-E/1ALE

o

r

w.

[12] 97 FLOWERING PLANTS

Types of Flower (continued).

III. CAMPION (Melandrium), protandrous.

A . Sketch the appearance of (a) a flower in the male stage, (b) one in the female stage.

B. Cut longitudinally a flower in the male stage and make a sketch to shew that the styles are immature
and not fully grown.

IV. PLANTAIN (Plantago major), protogynous.

A. Sketch the inflorescence of crowded flowers shewing the projecting styles and the drooping stamens.
Note that the flowers open at the bottom of the inflorescence first.

B. Draw a flower from the upper part, in the young (female) stage, with the unripe stamens hidden in the
corolla ; also a flower in the later male stage from the lower part.

[13]

Fruits.

98

FLOWERING PLANTS

I. SWEET PEA (Lathyrus odoratus) (Papilionatcz}.

Sketch the young fruit (pod) shewing the remains of the stigma and the persistent calyx. Split it longitudinally
and draw the young seeds attached to one ridge of the fruit wall. Compare it with your drawing of the flower
of Cytisus. In the older pod draw the row of nearly ripe seeds.

II. CHERRY (Prnnus cerasus) (Rosacece).

A. Sketch a flower cut open longitudinally, shewing the receptacle and the arrangement and manner of
attachment of (a) the sepals, (b) petals, (c) numerous stamens, (d) single carpel.

B. Cut a longitudinal section of a very young Cherry fruit. Observe the pericarp (fruit wall) consisting
of epicarp (skin), mesocarp (flesh) and the thickening endocarp (stone) ; also the testa and endosperm and embryo
of the young seed (kernel).

C. Sketch a ripe Cherry fruit shewing the scar of the style and the longitudinal groove representing the suture
(joined margins) of the carpel. Remove the stalk and notice on it the scar of the attachment of the receptacle-tube.

D. Break the stone and examine the ' kernel ' or seed containing the resting embryo.

A

[13] 99 FLOWERING PLANTS

Fruits (continued).
III. PEAR (Pyrus communis) (Rosacece).

A . Sketch a longitudinal section of an old Pear flower, shewing (a) receptacle-tube fused with the styles above,
(b) sepals, (c) stamens, (d) styles, (e) ovary and ovules.

B. Draw transverse and longitudinal sections of a very young Pear fruit and observe the carpels becoming
surrounded by the fleshy receptacle.

C. Sketch a ripe Pear in longitudinal section shewing (i) the stalk with the vascular cylinder continued
up to the base, through the central column and round the sides of (2) the carpels with horny walls (pericarp -
' core ' of the pear) and cavities containing (3) the seeds (' pips '), (4) the fleshy receptacle completely surrounding
the carpels, (5) the styles, (6) the remains of sepals and stamens surmounting the whole.

A

[13]

Fruits (continued).

100

FLOWERING PLANTS

IV. SYCAMORE (Acer pseudo-platanus).

A . Make a sketch of the ripe dried fruit.

B. Dissect one of the fresh half-fruits to shew the thin testa and the green coiled embryo.

C. Make a drawing of a section through the ripening ovary of the flower of Sycamore. Note the two ovules
in each loculus, and also the outgrowths which become the wings of the fruit.

V. DANDELION (Taraxacum officinale) (Composite).
Sketch a fruit of Dandelion to shew the pappus.

VI. HERB BENET (Geum urbanum) (Rosacece).

A. Sketch a fruit-head cut in half longitudinally, to shew the numerous achenes borne on the receptacle.

B. A single fruit (achene) shewing the hooked style, and the stigma which breaks off.

VII. SHEPHERD'S PURSE (Capsella).

Sketch various embryos under a high power illustrating different stages in development ; note the suspensor.
the young spherical embryo and an older embryo shewing the two cotyledons.

[14] 101 FLOWERING PLANTS

Seeds and Germination.

I. SEEDS WITH FOOD MATERIAL IN THE COTYLEDONS, WHICH REMAIN BELOW ON GERMINATION.
i. BEAN (Vicia faba).

A. Sketch a seed, noting the testa, the hilum, and the position of the micropyle. (By squeezing a soaked
seed a drop of water is forced out through the micropyle.)

B. Split the seed longitudinally, and sketch a cotyledon, the radicle, hypocotyl and plumule.

C. Make a series of sketches of germinating seeds and seedlings in different stages, shewing the radicle,
hypocotyl, plumule, cotyledons ; primary root and its lateral branches; stem and first foliage leaves: also the developing
axillary buds in the axils of the cotyledons.

[14] 102 FLOWERING PLANTS

Seeds and Germination (continued}.

SEEDS WITH FOOD MATERIAL IN THE COTYLEDONS, WHICH ARE RAISED ON GERMINATION.
GOURD (Cucurbita}.

A. Sketch a seed of Cucurbita. Notice the hilum and a pit in the testa which marks the position of the
vascular bundles of the seed-stalk. Split the seed lengthwise and observe the testa, the greenish layer of nucellus,
two cotyledons, radicle and very minute plumule.

B. Make a series of drawings illustrating the pulling out of the cotyledons from the testa, the straightening
of the hypocotyl and the expansion and growing of the cotyledons ; note the radicle, the hypocotyl, the peg or
heel, plumule, cotyledons and foliage leaves differing in shape from the cotyledons.

SEEDS WITH FOOD MATERIAL STORED OUTSIDE THE EMBRYO — COTYLEDONS RAISED ON GERMINATION.

CASTOR OIL SEED (Ricinus). A. Remove the testa from a Ricinus seed, exposing the hollow white mass
of oily endosperm ; split it open and observe the embryo in the middle. Draw the embryo shewing the thin
cotyledons, the radicle, hypocotyl and plumule.

B. Sketch a series of Ricinus seedlings, shewing the gradual straightening of the hypocotyl and the expansion
and turning green of the cotyledons.

[14] 103 FLOWERING PLANTS

Reserve food materials in seeds and tubers.

I. CASTOR OIL SEED.

Examine sections of the endosperm and observe the aleurone grains of reserve proteid in the cells. Oil is
also present in very minute drops.

II. BEAN.

Examine sections of the cotyledon and observe the reserve starch-grains surrounded by fine granules of
proteid in the cells.

III. TUBER OF POTATO (Solatium tuberosum).

Examine a small section of a Potato including the brown skin and a little of the internal tissue ; stain with
Schulze's solution and mount. Sketch a portion of the section to shew the cork cells of the skin, and the darkly
stained starch-grains in the large parenchymatous cells of the internal tissue. "*

"

Oo^^v^v^t*^-^ -SMlA^L.

3 /.

(^

€$
H&.

y/^
a^x'/^

li^^7

«^fe^f-:

/-•*

x o •

*

r^f t£>

32-

.

V — «/

34.

\*

1

~T£;

Up*

BIOLOGY
LIBRARY

UNIVERSITY OF CALIFORNIA LIBRARY

•'-;-- -