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the normal which was no doubt due to the refrigeration, — in 

 this case an increase of dark pigment. Eggs were laid by 

 some of these abnormal specimens, the resulting larvae were 

 reared under normal conditions, and the butterflies on 

 emergence again showed a divergence from the normal form 

 which, though slight, was in the same direction as that of 

 their parents. Similar results with the same species were 

 afterwards obtained by Weismann himself. A still more 

 marked confirmation was supplied by Fischer. Pupae of 

 Chelonia caja were subjected to an artificially lowered 

 temperature, and some of the resulting moths showed an 

 extreme degree of melanism. Two of these artificially-produced 

 aberrations were paired, and their offspring were reared 

 under normal conditions. Among the latter were specimens 

 which exhibited in greater or less degree a tendency towards 

 the artificially-induced melanism of their parents. Here we 

 have an excellent case of the apparent transmission of an 

 acquired character. In the light, however, of Weismann's 

 acute reasoning on the subject of C. phlaeas, there is every 

 justification for believing that the same interpretation is valid 

 in the present case. The modification is not inherited from the 

 soma of the parent, but is consequent upon the direct action of 

 the external influence upon that parent's germ-plasm. 



But all this pioneer work, important and excellent as it is, 

 must yield the palm for completeness and cogency to the 

 laborious researches conducted by William Lawrence Tower, 

 whose treatise entitled "An Investigation of Evolution in 

 Chrysomelid Beetles of the Genus Leptinotarsa " is a perfect 

 storehouse of valuable biological material, all derived from 

 the minute study of a single genus of Coleoptera. This 

 admirable publication, which appeared in 1906 under the 

 auspices of the Carnegie Institution of Washington, has 

 perhaps in this country hardly met with the attention which 

 it deserves ; though now that Professor Bourne, in his recent 

 Presidential Address to the Zoological Section of the British 

 Association, has drawn public attention to the work, it may 

 be expected that greater appreciation will be shown of the 

 extremely interesting results which it contains. 



Among the numerous and carefully-planned experiments 



