290 - Multicellular Animals, Especially Man 



cytes of vertebrates, except for the mammals, 

 possess nuclei. 



Leucocytes are of various kinds according 

 to their form and origin (p. 322); and not 

 all leucocytes are able to migrate through 

 the walls of the capillary blood vessels into 

 the tissue spaces. The lymph — or body fluid, 



as it is more frequently called in lower ani- 

 mals — resembles blood, except that lymph 

 contains less protein and no erythrocytes. 

 Lymph fills the tissue spaces; and in 

 a majority of animals, the lymph cir- 

 culates slowly through these tissue spaces (p. 

 33-1). 



9. 

 10. 

 1 1. 



TEST QUEST 



Distinguish carefully between: 



a. the vitelline membrane and the fer- 

 tilization membrane 



b. activation and fertilization 



c. activation and parthenogenesis 



d. natural and artificial parthenogenesis 13. 



e. haploid and diploid parthenogenesis 

 Describe an experiment proving that activa- 

 tion and fertilization are separate functions 

 ol the sperm. 14. 

 Distinguish between (he acrosome filament 

 and the fertilization cone. Explain the func- 

 tion ol cadi. 



Is there any relation between the quantity 

 ol yolk in an egg and the length ol the em- 

 bryonic period? Explain. 



Explain the significance of polarity in the 

 egg. 



Why is the middle piece of the sperm im- 

 portant? 



What is a blasiula? How does the blastula 15. 

 derived from a homolecithal egg differ from 

 one derived from a telolecithal egg (for ex- 

 ample, a frog's egg)? 



What is a gastrula and how does it arise? 16. 

 Identify: (a) the archenteron; (b) the ecto- 

 derm and endoderm: and (c) the blastopore 17. 

 and blastocoel. 



Explain three ways in which mesoderm may 18. 

 arise in various embryos. 



Differentiate between diploblastic and triplo- 

 blastic animals, citing an example ol each. 

 Enumerate the adult structures (in vertebrate 19. 

 animals) that are derived from: (a) the ecto- 

 derm: (b) the endoderm: (c) the mesoderm. 

 A. Describe the origin of the coelom and ex- 



IONS 



plain how the coelom is related to the so- 

 matic and visceral lavers of mesoderm, and 

 to the mesentery. 



B. Explain the importance of the coelom in 

 higher animals generally. 



Explain the distinctive features that dif- 

 ferentiate: 



a. vertebrates from invertebrate animals 



b. vertebrates from other chordate animals 

 Identify, locate, and explain the origin of: 



a. the neural groove, the neural folds, 

 and the neural tube 



b. the brain and spinal cord 



c. the notochord 



d. the vertebrae, including the neural 

 arches and centra 



e. visceral and skeletal muscle 



f. the gill slits and the Eustachian tubes 



g. the lungs, liver, and pancreas 

 h. the blood and lymph vessels 



Trace the development of the digestive tract 

 (in vertebrates) from the time of invagina- 

 tion until the saccular enteron becomes tu- 

 bular. 



What are the fundamental tissues and how 

 are they differentiated one from another? 

 Specify four kinds of epithelia and explain 

 the distinctive features of each. 

 Specify the three kinds of muscle tissue and 

 describe the distinctive features of each kind. 

 In what ways are all kinds of muscle similar 

 to each other. 



Identify: (a) yellow fibrous connective tis- 

 sue: (b) fibroblasts: (c) chondrin; (d) chon- 

 droblasts; (e) Haversian canals; and (f) la- 

 cunae. 



FURTHER READINGS 



1. Ourselves Unborn, by George W. Corner; 

 New Haven, 1944. 



2. Embryos and Ancestors, by G. R. DeBeer; 

 Oxford, 1958. 



3. Human Embryology, by B. M. Patten: Phila- 

 delphia. 1953. 



4. Developmental Anatomy, by L. B. Arey; 

 Philadelphia, 1954. 



