BODY SIZE AND CELL SIZE 163 



Rabl ('99) found that the size of cells of the crystaUine lens 

 was practically constant, but the cell number a variable one, 

 depending upon the size of the organ. Boveri ('04) also found 

 that in dwarfs and giants of the human species the size of epithe- 

 lial cells from the tongue and of bone corpuscles from a phalanx 

 agreed perfectly with those from an individual of normal size. 



Chambers ('08), on the other hand, has questioned the view 

 that a certain cell size is characteristic of a species or race; he 

 finds that the size of an individual frog, and the size of its con- 

 stituent cells, depends upon the size of the egg from which it 

 came. In agreement with the earlier work of Morgan ('04), he 

 has found that the size of the frog's egg may vary considerably; 

 whether laid by the same individual, or by different ones, the 

 diameters of eggs of extreme size may vary as much as 1 : 3. 

 The smaller eggs give rise to smaller tadpoles and frogs, which 

 are composed of smaller cells, than those derived from larger eggs. 

 He beUeves with Popoff ('08) that the initial cause of the varia- 

 tions in the sizes of eggs is to be found in unequal division of the 

 nucleus or plasma of the oocytes. 



Popoff ('08) holds that sperm cells as well as egg cells vary in 

 size. He supposes that when a large egg is fertilized by a large 

 spermatozoon a large individual with large cells results ; whereas 

 from small eggs and small spermatozoa small individuals with 

 small cells arise. He admits that the operations of this law may 

 be obscured by two other conditions, viz., (1) various factors which 

 limit or inhibit growth, and (2) rich nourishment which influences 

 only the number of cells, and not their individual size. He 

 affirms, therefore, that body size is not inherited as commonly 

 supposed — it has no specific representative in the germ plasm; 

 only the size of cells, not the size of individuals, is inherited. 



Berezowski ('10) has made a study of cell size in relation to body 

 size in white mice, varying in age from ten days to five months, 

 and in body volume from 4 cc. to 25 cc. He finds that with the 

 growth of an animal there is an increase in the cell size and nuclear 

 size, particularly in the length of cells and of nuclei of the 

 intestinal epithelium adjoining the pylorus. In a second paper, 



