396 



SCIENCE. 



[N. S. Vol. VIII. No. 195. 



Variation in the Shell of Helix nemoralis, in the 

 Lexington, Fa., Colony. By Peofessoe 

 James Lewis Howe. 

 Theee series of this introduced snail were 

 collected from gardens. There were over 

 1,000 shells in each lot. The colony origi- 

 nated in 188.3. The conclusions reached 

 from a study of these series are : (1) the 

 variations tend in general along the same 

 lines as in Europe ; (2) the tendency of 

 variations differs in different portions of the 

 Lexington colony. The author gave a 

 tabulated list of the varieties known in the 

 Lexington colony, of which the total num- 

 ber was 385. Of these 277 were enumerated 

 for the first time. 



Variation versus Heredity. By Peofessor H. 



S. Williams. 



Variation, and not heredity, is considered 

 the fundamental characteristic of the phe- 

 nomena of organisms. The arguments for 

 variation versus heredity are as follows : 



1. In any concrete case of natural selec- 

 tion, or other similar processes, the actual 

 result of selection is the retarding and 

 checking of variation, and the offspring 

 necessarily evolves more slowly than its 

 parent, in direct proportion to the efficacy 

 of natural selection. 



2. That the organic processes by which 

 variation takes place in an organism differ 

 from the ordinary process of development 

 in individual growth only by passing be- 

 yond the limit reached by the ancestor, and 

 hence variation is but a phase of the funda- 

 mental genetic process peculiar to living 

 organisms. 



3. That every act of variation is anterior 

 to experience, and thus is necessarily origi- 

 nal and genetic ; whereas every hereditary 

 act is necessarily secondary to and the 

 result of experience, and the law of heredity 

 must therefore be acquired in the process of 

 evolution and is not fundamental. 



4. That as to struggle for existence the 



most strenuous effort made (both by paren 

 and offspring) in the course of organic 

 processes is that which produces antago- 

 nism of interests. On the part of the parent 

 it parts with that which has cost it the 

 greatest expenditure of energy, and on the 

 part of the offspring the result is the loss, in 

 part or wholly, of the only source of its liv- 

 ing up to the moment of the struggle. 



.5. That the orthodox view is inconsistent 

 in so far as it recognizes mutability as ap- 

 plicable only to organic species and clings 

 to the idea of the immutability of the more 

 fundamental units of biology, viz., the in- 

 dividual and the cell and the protoplasmic 

 states of matter. 



These considerations bring us to a point 

 of view in which heredity and variation 

 hold a different relation to evolution than 

 in the ordinary working hypothesis of bi- 

 ology. If this point of view presents the 

 facts in their true relations we must seek 

 for the immediate determining causes in 

 variation, not in natural selection, nor in 

 any of the environmental conditions, either 

 direct or indirect, by which hereditary 

 repetition is established, but in the phe- 

 nomena of individual growth and develop- 

 ment, and the more fundamental processes 

 of cell growth and metabolism. (To be 

 published in the American Naturalist.) 



Localized Stages in Growth. By Dr. Robert 



Tracy Jackson. 



As shown by Hyatt and others, stages in 

 growth occur in the young and old organ- 

 ism, the adult representing full specific char- 

 acters. The ontogeny of the individual there- 

 fore repeats, in an epitomized form, the 

 phylogeny of the group. 



From studies of animals and plants it has 

 been found that stages may occur in localized 

 parts throughout the life of the individual. 

 In organisms that during growth present a 

 serial repetition of similar parts there is 

 often an ontogenesis of such parts, which is 



