15~AN ATOMY OF THE DOG 



The Womb and Vacina 



The womb or uterus is the cavity where the 

 feti or puppies develop. It consists of a short 

 body and two longr narrow horns, which 

 horns connect with the fallopian tubes. 



The opening of the uterus is into the vagina 

 and is known as the os uteri, the mouth of the 

 womb. 



The lower part of the external opening of 

 the vagina is called the vulva. Just within the 

 vulva is a small prominence known as the 

 clitoris. 



A full description of the sexual organs of 

 both sexes of the dog, their functions and ac- 

 tivities, is given in the author's Principles of 

 Dog Breeding, now in its third edition. 



When quiescent, the penis is inclosed at its 

 end in a folded skin called the prepuce or 

 sheath. 



Sexual Organs of the Female 



In the female the reproductive organs are 



the two ovaries, two fallopian tnbes and the 

 uterus or womb. 



The ovaries are two small oval bodies, each 

 one situated close to a kidney and each one 

 in a pouch known as peritoneal, namely the 

 bursa ovarii. 



In the ovaries are graafian particles, blad- 

 der-like, which when fully developed are filled 

 with fluid and ova or eggs. These when ripe 

 burst away from the ovaries and go down 

 thru the fallopian tubes toward the opening of 

 the womb, this however only during the semi- 

 annual heat or season period. 



Connect Ovaries and Womb 



The fallopian tubes, one on each side, form- 

 ing a rough U, extend from the ovaries to the 

 corresponding horn of the uterus, opening 

 thru a very small hole. Cutting this channel 

 does not eliminate heat but makes pregnancy 

 impossible. 



X. SENSUAL SYSTEM OR ORGANS OF SENSE 



The organs of sense, of course, are the or- 

 gans of the five common senses. We shall de- 

 scribe them briefly. 



Eye has Free Movement 



The eye is in the shape of a globe and is 

 lodged in the orbital cavity of the skull. It 

 moves in various directions with the aid of 

 miiscles and is connected to the brain by 

 means of the optic nerve. 



Breed standards call for various shapes of 

 eyes — round, oval, prominent, small, large, al- 

 mond. These shapes refer to the visible por- 

 tion as in reality the eye always is of the 

 same round or ball shape. 



No Lower leashes 



The eyelids upper and lower protect it in 

 front. There is a third eye lid or haw, mem- 

 brane nictitans, in the inside comer. A cold 

 may inflame and enlarge is considerably. 



The dog does not have any lashes on the 

 lower eyelid. 



The lachrymal gland facilitates the move- 

 ment of the eyelids and also secretes a fluid to 

 wash away foreign bodies. 



Construction of the Eye Globe 



The globe itself, or eye proper, the eye ball, 

 has a content of semi-fluid inclosed by three 

 coats. 



The outer skin of the outer coat is the cor- 

 nea, transparent and very tough. 



The middle of the three coats is a vascular 

 membrane, visually of black pigment. A part 

 of this projects forward into the interior of the 

 eye as the iris. 



Iris Determines Color of Eye 



The iris is a muscular curtain which con- 

 tracts or expands under the influence of light 

 and so acts as a lens. Its center is the pu- 

 pil. The iris determines the color of the eye. 

 Eye Acts like a Camera 



The crystalline lens is just behind the pupil 

 of the eye. It serves the purpose of focusing 

 the rays of light upon the retina. If the light 

 cannot pass thru the lens, this opaque condi- 

 tion is one of cataract. 



Inner Contents of Eye Flaidlike 



Between the cornea and the lens is the 

 clear watery fluid, the aqueous humour. Back 

 of this is the jelly-like material known as 

 vitreous humour. 



The very back of the eye is the retina, a 

 sheet of nerve tissue. 



Three Sections in Ear 



The ear. of course, is the organ for hearing. 

 The auditory nem^e carries the sound impres- 

 sions from ear to brain. 



The three parts of the ear are external, 

 middle and internal. 



Dog's Ear Very ExpressiTe 



The external is a trumpet-shaped piece of 

 cartilage covered by skin ; it varies in size and 

 shape in the various breeds. It may be car- 

 ried vertical or downward or in various other 

 postures. It can be shaped voluntarily in such 

 way toward the source of sound in order that 

 the impulses may better be contacted by the 

 dog. 



Breathing thm the Ears 



The middle ear known as tympanum is a 

 small cavity, protected against the outer ear 

 by the tympanic membrane or drum. From this 

 dnmi runs the Eutachian tube, thru which 

 air is admitted in order to equalize the pres- 

 sure on each side of the drum. Thus one can 

 hold his nose shut, blow into his nose, and 

 force the air out thru the ears, often an action 

 of relief when one ascends in an aeroplane or 

 moves up the side of a mountain. 



Here also is the balancing mechanism for 

 the body. If injured, it causes staggering and 

 falling. 



Ear "Wired" for Sound 



Three small bones are found within the 

 middle ear ; they connect with the internal ear, 

 a complex structure, which contains a lymph- 

 like fluid in which small bony bodies float. 

 When a sound wave is received into the ex- 

 ternal ear, the drum vibrates in the middle ear 

 and from it the vibrations are transmitted to 

 the fluid of the internal ear, thence to the 

 brain thru the fibers of the auditory nerve. 



It is easy to pierce or damage the ear drum. 

 Consequently probing into the ear should be 

 done carefully. 



Several Tasters 



The tongue is the organ of sense, but not 

 alone for to it must be added the mucous 

 membrane or inner lining of the mouth. Both 

 contain taste buds or cellular organs which 

 convey the sense of taste to the brain thru 

 the fifth and ninth cranial nerves. 



The Nose is Mndi of the Dog 



The olfactory nerves are the nerves of 

 smell, distributed generously over the lining of 

 the posterior or rear part of the nasal cavity. 



