CELL SIZE AM) MK'IAUOLIC ACTIVITY IN AMPHIBIA. 349 



fruit-eating bats have distinctly larger corpuscles than the insect 

 caters. Among the birds the largest corpuscles are found among 

 the Cursores, and the smallest among the insect-eating passeri- 

 form birds. Among the reptiles the Chelonia have distinctly 

 larger corpuscles than the Sauria. The corpuscles are much 

 larger in the Caudal a than in the Salientia, and larger in the 

 Elasmobranchii than in the Pisces. 



< )ther workers who have given measurements of red blood cells 

 are VYeckler (1863 . Malassez (1872'. Form. id iss> \Vormley 

 (1888), and Forrest (1913). Forrest and Malassez also made 

 count-. The-e run in inverse ratio to the -i/e, although there 

 an < -\ i rptions. A comparison of the measurements of amphibian 

 < orpu-cle- by different workers will be found later. Reichert 

 and Urottn i'o(>) review the work which has been done on red 

 blood cell -i/e and state that attempt- to correlate the size of 

 the-e ( ell- \\ith the rapidity of the animals' movements are 

 founded on in-ntln ient or erroneous data. 



Hartmann n>>\i)a) shows that the chloroplasts in developing 

 J-'.liH/fti leaves are smaller and more numerous in plants grown at 

 higher temperatures, as contrasted \\ith the larger and U 

 numerou- chloroplasts in plants grown at lo\\er temperatu: 

 Since the metabolism of the leaves is certainly speeded up with 

 increased teni|)erature. this observation fall- well in line with 

 the idea that a high rate of activity is assot iatcd with small si/e. 



('lumber- too- shows that there is considerable variation in 

 the -i/e of the egg- of Rana escnlenta and K. tcnifwriirin. that the 

 3 de\elop a little more rapidly than the -mailer ones, 

 and that there is a much higher percentage of mortality among 

 -mall than anionv large eggs, especially when grown at higher 

 temperature-. He shows that the size of the cell- in the frog 

 varies \\ith tin -i/e of the egg from which the frog developed; 

 and that egg- allo\vel to develop at higher temperature- in\ar- 

 iably yield -mailer frogs with smaller cells than those developed 

 at louer temperature- -i/e taken at time of metamorphosis or 

 earlier). Tadpole- in crowded cultures are -mailer than tho-e 

 with more room, but this does not affect the size of the cells. 

 Morgan (1904) worked on dwarf frog eggs which had only 

 about half the volume of the normal eggs, and showed th.it the 

 cells in the developing dwarf embryos tend to remain -mailer 



