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THE AMERICAN NATURALIST 



[Vol.L 



levana-prorsa, for example, might in suitable diverse climates, 

 subarctic and tropical, respectively, be fixed as separate species. 



A. levana bred in Labrador, for example, where it could pro- 

 duce only one brood, probably would not show its pmrsa-produc- 

 ing tendency at all. This supposition is confirmed by Trybom's 

 observation (quoted by Weismann) that in Siberia, where a single 

 brood occurs yearly, it is levana only. Conversely, prorsa in the 

 tropics would perhaps eliminate all traces of levana, though of 

 this we can not be so confident. 



How much practically identical germ-plasm in different parts 

 of the world is masquerading as different species, because of the 

 diverse ways in which it reacts to different environments in which 

 it happens to be placed, has not been adequately investigated. 

 An interesting example of the sort among tropical reef fishes was 

 recently cited by Longley. 7 



Bodianus fulvus and B. punctatus are two color phases of one species 



The rapid interchange of reproductive habits between Sala- 

 mandra maculosa and the alpine atra when transferred respec- 

 tively to lowland or highland conditions, as described by Kam- 

 merer, 8 is probably also a case in point, due to fundamentally 

 similar germ-plasm in both forms. Such an assumption would 

 account for the inheritance of these readily acquired characters. 

 If the facts are correct, S. maculosa, by cold and drought, was 

 forced to assume the reproductive habits of the salamander of 

 the neighboring alpine regions named atra, producing two adult 

 larvae viviparously, rather than many (14-72) immature embryos 

 laid in water as is its habit in the warm, moist lowlands. Con- 

 versely, the alpine form was forced by heat and an ample water 

 supply to increase its fecundity from two to nine hirvie at a birth. 

 In both cases the "acquired characters" were inherited, as we 

 would expect them to be if the two kinds of salamanders, as 

 regards reproductive mechanism at least, have an identical or 

 similar genotype. The fact that the lowland form living at 

 higher altitudes has fewer young, and that the alpine form in 

 the lower regions of its range produces an abnormally large 

 number (viz., four) also points to the same conclusion. 



It is a possibility worth considering that somatic modification 

 accompanied by little germinal change may partially explain 



7 Carnegie Institution of Washington. Year Book. No. 14. 1915, p. 209. 



