276 CARNEGIE INSTITUTION 



(a) Much of the labor involved is of a routine nature, which can 

 be carried on by a moderately skilled gardener or attendant, and 

 thus the results may frequently be of greater value, because experi- 

 ments involving numbers may be prosecuted on a larger scale and 

 more problems undertaken. 



(b) Superiority of Equipment. The equipment would be of the 

 best, thus insuring more and better results. Accidents resulting 

 from improvised apparatus have spoiled many experiments, as wit- 

 ness the work upon breeding caterpillars. 



The problems to be undertaken are numerous ; the most important 

 would seem to be those mentioned in the introductory paragraph. 

 A few specific cases may be briefly cited : 



Problems to be Solved. 



1. Environment alterahility of the germ-plasms. 



(a) Peas are said, by Bailey, to be particularly susceptible to 

 the wetness of the soil in which they grow. Grow sweet peas which 

 self fertilize in a heavy muck and keep well watered. Grow others 

 in a loam never watered if outdoors. Grow the progeny in the re- 

 spective environments for many generations ; observe, first, what 

 divergence takes place in one generation ; and, second, to what de- 

 gree, if any, the divergence is cumulative in successive years. Each 

 year grow some plants from seeds of each set in an intermediate en- 

 vironment. Do they revert completely to a common type each year, 

 or are they found to retain, each year, more of their divergence? 



{h) Bring into cultivation some wild plants of a species which 

 has given rise to a cultivated variety. Carefully avoid selection. Ob- 

 serve whether successive generations, nevertheless, diverge from the 

 wild species. 



2. Inheritance of somatogenetic characteristics. 



(a) Some species, as the painted turtle, which both swims and 

 walks and has short generations, may be experimented upon in two 

 series. In one case they are confined to water; in the other, kept 

 from it. Observe as above. 



{b) Grow Chologaster, from which the blind fishes are descended, 

 in the dark. Observe as above. 



5. Isolation. 

 (a) Isolate two groups, of ten each, of a species which differ 

 abnormally in opposite directions from the normal conditions, e. g., 

 ten turtles lacking one pair of scutes and ten turtles with a supernu- 



