14 PROFESSOR A. M. MARSHALL. 



The chick embryo, on the other hand, has an abundant supply 

 of food in the egg itself ; it has no occasion to spend time searching for 

 food, but can devote its whole energies to the further stages of its 

 development. Hence, except in the earliest stages, the chick develops 

 more rapidly than Amphioxus, and attains its adult form in a much 

 shorter time. 



The tendency of abundant food yolk to lead to shortening, or 

 abbreviation of the ancestral history, and even to the entire omission 

 of important stages, is well known. The embryo of forms well 

 provided with yolk takes short cuts in its development, jumps from 

 branch to branch of its genealogical tree, instead of climbing steadily 

 upwards. 



Thus the little West Indian frog, Hylodes, produces eggs which 

 contain a larger amount of food yolk than those of the common 

 English frog. The young Hylodes is consequently enabled to pass 

 through the tadpole stage before hatching, to attain the form of 

 a frog before leaving the egg ; and the tadpole stage is only 

 imperfectly recapitulated, the formation of gills, for instance, being 

 entirely omitted. 



The influence of food yolk on the development of animals is 

 closely analogous to that of capital in human undertakings. A 

 new industry, for example, that of pen-making, has often been 

 started by a man working by hand and alone, making and selling 

 his own wares ; if he succeed in the struggle for existence, it soon 

 becomes necessary for him to call in others to assist him, and to 

 subdivide the work : hand labour is soon superseded by machines, 

 involving further differentiation of labour; the earlier machines are 

 replaced by more perfect and more costly ones; factories are built, 

 agents engaged, and in the end, a whole army of workpeople employed. 

 In later times a man commencing business with very limited 

 means will start at the same level as the original founder, and 

 will have to work his way upwards through much the same stages, 

 i.e., will repeat the pedigree of the industry. The capitalist, on the 

 other hand, is enabled, like Hylodes, to omit these earlier stages, and 

 after a brief period of incubation, to start business with large factories 

 equipped with the most recent appliances, and with a complete staff of 

 workpeople, i.e., to spring into existence fully fledged. 



