828 TEST QUESTIONS FOR STUDENTS 



remains of structures which were of use and well developed in ancestral 

 forms. A good example is the remnant of a third eyelid in man. The 

 Eustachian tube corresponds to the first gill-cleft ; a bee's sting probably 

 corresponds to a pair of abdominal appendages ; the incus of the 

 mammalian ear probably corresponds to the quadrate. These being func- 

 tional should not be called vestigial, but rather transformed structures.] 



1 68. Discuss some of the peculiarities of structure and habit which 

 help animals to hold their own in the struggle for existence, giving 

 precise examples. 



169. Explain what is meant by Discontinuous Geographical Distribu- 

 tion and give two examples. 



170. Explain what is meant by Isolation, and give examples. 



171. Explain what is meant by Protective Resemblance and by 

 Mimicry. Give examples. 



172. Explain what is meant by the Struggle for Existence, and give 

 definite illustrations. 



173. Explain what is meant by Mendelism, and give definite illustra- 

 tions. 



174. Make a comparison of, integumentary structures through the 

 Vertebrate series. 



175. Write a short note on three of the following : A moth flying 

 into a candle, a starfish surrendering an arm, the rattle of a rattlesnake, 

 a shower of gossamer, a hibernating bat, a sheep chewing the cud, a 

 butterfly's chrysalis. 



176. Explain what is meant by the Web of Life, and give a variety 

 of illustrations. 



177. Describe at some length three or four of the many different ways 

 in which the safety, nutrition, and general well-being of very young 

 animals is secured. 



178. Why is it that archaic types, such as Onychophora, Cepha- 

 lochorda, Dipnoi, have such a wide geographical representation ? 



179. Mention some of the chief ways of getting food. [Vegetarian, 

 carnivorous, feeding on microscopic organisms, feeding on detritus, 

 saprophytic, helped by symbions, helped by chlorophyll, helped by com- 

 mensals, parasitic.] 



1 80. In the sea we may distinguish producers of food, consumers 

 of food, middlemen that make food more available for consumers, and 

 middlemen that make the dead bodies or waste-products of consumers 

 available for the fundamental producers, namely, plants. Make this 

 concrete with definite examples. 



181. Distinguish the three grades of parturition in mammals. [The 

 oviparous Monotremes, the prematurely-bearing Marsupials, the 

 ordinary Placentals.] 



182. Explain the present-day geographical distribution of Marsupials. 



183. Explain the general physiology of hibernation so far as it 

 is understood. 



184. Give a short account of the pedigree of the modern horse. 



185. What are the deep differences between a living animal and 

 an engine ? 



1 86. What are the first four great events in the embryonic develop- 

 ment of a Vertebrate after the segmentation of the ovum ? [The estab- 



