SECT. 2] 



AND WEIGHT 



471 



the same gestation time reach, when full-grown, very different weights 

 (e.g. the antelope and the hippopotamus). However, if the weight 

 when adult is plotted against the gestation time on double-log. paper, 

 a straight-line relation is obtained, individual points not lying very 

 far from the mean. The only reason for using double-log. paper 

 here is the convenience of getting all the data on to the same 



Table 60. Przibram's figures. 



Animal 



Chimpanzee ( 7>o^/o^fe^ m^«r) ... 



'M.acacus {Macacus siniciis) 



Mandrill {Cynocephalus papio) 



Uistiti (Callithrix jaccus) ... 



L.emuT (Lemur catta) 



Lion (Felis leo) 



Puma {Felis concolor) 



Ermine {Mustela erminea) 



Wolf (Canis lupus) 



Bear (Ursus arctus) 



Seal {Phoca) 



German marmot {Cricetus frummtarius) . 



Mouse (Mus musculus) 



Rat {Epimys rattus) 



Rabbit {Lepus cuniculus) ... 



Guinea-pig {Cavia cobaia) 



Cow {Bos taurus) ... 



Sheep {Ovis aries) 



Goat {Capra hircus) 



Stag {Cervus elaphus) 



Roedeer {Cervus capreolus) 



'EAand {Alces palinatus) 



Camel {Camelus dromedarius) 



Moschus {Moschus moschiferus) 



Pig {Sus scrofa) 



Hippopotamus {Hippopotamus amphibius) 



Rhinoceros {Rhinoceros unicornis) ... 



Horse (Eguus caballus) 



Donkey {Equus asinus) 



Elephant {Elephas indicus) 



Kangaroo-rat {Hypsiprymnus cuniculus) . . 



Opossum {Didelphys virginiana) ... 



graph. The line does not meet the co-ordinates at the zero point; 

 it cuts the time scale, no matter what units are taken. This means 

 that no matter how small the mammal, an appreciable time 

 has to be taken in development, and in the case of a mammal 

 as small as a gnat, a surprisingly long gestation time would be 

 observed. Thus the mouse, which is 259,000 times as small as an 

 elephant, does not have an incubation period 259,000 times as 



