GENERAL BIOLOGY 



B. PHYLOGENY. Development of Races, Species and larger 

 subdivisions. 



I. VARIETIES AND SPECIES. 



1. Varieties. In a large series of individuals of the same species 

 pick out and draw individuals which represent the mean and the 

 extremes of variation. 



2. Species. In a genus containing a large number of species, 

 pick out and draw species which represent the mean and the ex- 

 tremes of the series. 



II. HOMOLOGIES. 



a. Comparative Anatomy. 



1. Draw and label corresponding parts of the limb skeletons 

 of three vertebrates, having different modes of locomotion. 



2. Draw and label corresponding teeth of three vertebrates, 

 which eat different kinds of food. 



3. Draw and label corresponding parts in the appendages of a 

 lobster, or crayfish, and a crab. 



4. Draw and label corresponding parts of the skeleton of a 

 starfish and a sea-urchin. 



How are such likenesses (homologies) to be explained? 



b. Comparative Embryology. 



1. Study and draw the adult and larva of an ascidian, and of 

 a barnacle, and show how embryology throws light on phylogenetic 

 relationships. 



2. Compare the branchial clefts in an embroyo chick and shark, 

 and indicate the phylogenetic significance of this resemblance. 



c. Paleontology. 



Study in the Museum the paleontological history of some family 

 of animals, and trace its Evolution. 



III. EXPERIMENT. 



With the aid of books which will be assigned you, describe the 

 principal races of some one domestic animal or cultivated plant and 

 compare them with the original wild stock. 



IV. FACTORS OF EVOLUTION. 



Explain the origin of the peculiar structures of the specimen 

 assigned you according to the following theories : ( I ) Lamarckism. 

 (2) Darwinism. (3) Mutation. 



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