268 VETERINAEY STATE BOARD 



Name the secretory glands that are active in fetal life. 

 See answer to preceding question. 



State the duration of pregnancy in (a) the mare, (b) the cow, (c) the 

 sow, (d) the bitch, (e) the ewe. 



(a) 330-340 days; (b) 270-280 days; (c) 115-120 days; (d) 

 58-65 days; (e) 145-155 days. 



Trace the journey of the ovum from incipiency to the accomplishment 

 of fertilization. 

 After rupture of the Graafian vesicle, the ovum escapes and is 

 conveyed into the Fallopian tube by means of the fimbriated extrem- 

 ity of the same. It passes down the tube to the uterus where it is 

 met by the spermatozoa. This meeting may take place in the 

 oviduct but the ovum usually continues to descend to the uterus. 



Describe physiologically the impregnation of the ovum. 



The spermatozoa pass through the outer layer of the ovum 

 (zona pellucida). The germinal vesicle, or nucleus of the ovum, 

 disappears and a somewhat opaque, embryonal cell (pronucleus) 

 succeeds. With the formation of the pronucleus, the vitellus becomes 

 separated from the zona pellucida and begins to rotate therein. 

 Then a segmentation of the embryonal cell into two portions occurs ; 

 each of these two portions divide into two, etc. This division and 

 subdivision continue for a short time (2 or 3 days) until the stage 

 of morula is reached. At this stage the mass is still spherical, is 

 surrounded by the vitelline membrane and the zona pellucida, and 

 contains the mass of cells resulting from the repeated divisions 

 before mentioned. After this the mass enlarges, changes shape, and 

 the germinal layers form. 



Give the composition of cow's milk. 



Water 87 



Solids X3 



Albumin 3_3q 



Fat 4.00 



liactose 4.95 



Salts 75 



State the difference in the composition of the milk of the mare and 

 that of the cow. 

 See answer to preceding question. 



Mare's milk contains more water and sugar but less fat and 

 albumen than cow's milk. 



