September 13, 1906] 



NA TURE 



487 



Is it |jo=sibIe to state the gist of the contribution 

 wliich the almost too analytic author has to maliC? 

 Like draws to like; animals with similar acquired 

 iharncters tend to come together and keep together 

 ill habitudinal segregation; "isolation" and " selec- 

 lion " in their varied forms work on inborn variations, 

 and the habitudinal segregation is replaced by a 

 stabler racial segregation. Segregate breeding, forti- 

 fied by physiological and psychological incompati- 

 bilities, results in divergent evolution. " The whole 

 process of bionomic evolution, whether progressive or 

 retrogressive, whether increasingly ramified and 

 divergent, or increasingly convergent through amal- 

 gamation, is a process by which the limitations of 

 segregate breeding are either set up and established 

 or cast down and obliterated." It is of value that all 

 (he various possibilities and actualities of segregation 

 should be analysed out and illustrated as Mr. Gulick 

 has so painstakingly and ingeniously done ; and 

 another great merit of the book is the insistence on the 

 fact that, even in the case of invertebrate animals, 

 members of the same species, exposed to the same 

 environment in isolated groups, will often arrive at 

 divergent methods of dealing with the environment, 

 and so subject themselves to divergent forms of 

 selection. Just as the social group may learn to 

 determine its own social evolution, so, Mr. Gulick 

 maintains, justly, we think, that the animal is in some 

 measure master of its fate, and that changes in the 

 organism are not controlled in all their details by 

 changes in the environment. We are too much given 

 to ranking the environment always first and the 

 organism second ; Mr. Gulick thinks this is putting 

 ihe cart before the horse; and in this insistence on 

 active or endonomic selection, he does not stand alone. 

 For, as he says, there has been during the past ten 

 or fifteen years an increasing recognition of the fact 

 that not only sexual selection but other autonomic 

 factors are more or less effective in controlling the 

 forms of selection, and, therefore, in controlling the 

 transformations of organisms. Do we not thus reach 

 one explanation of the continuous advance — the deter- 

 minate evolution — of certain large classes of animals ? 

 The recognition of autonomic factors in the process of 

 evolution is giving new insight into the self-developing 

 I'ndowments of the organic world. In conclusion, we 

 must direct special attention to the fact that Mr. 

 iiulick's contribution to our understanding of the 

 intricate factors of evolution is all the more valuable 

 that he rises from biology to sociology — from the 

 Hawaiian snails to Man himself. J. A. T. 



ENTOMOLOGICAL STUDIES. 

 The Hope Reports. Vol. v., :903-6. Edited by 

 Prof. E. B. Poulton, F.R.S. (Oxford: Printed for 

 Private Circulation by Horace Hart, 1906.) 



THIS is a substantial volume, some hundreds of 

 pages being occupied by prints of papers con- 

 tained in the Transactions of the Entomological 

 Society of London or by prints of that society's pro- 

 ceedings, one, however, being of a paper in French 

 contributed by Prof. Poulton to the " .\nnales de la 

 NO. IQ24, VOL. 74] 



Soci^te Entomologique de France." These prints 

 comprise a useful r^sumi of recent papers and dis- 

 cussions at the meetings of the English Entom- 

 ological Society during the last three years on 

 bionomic subjects, as well as the two presidential 

 addresses of Prof. Poulton to that society on the 

 questions, "What is a Species?" and " .\re 

 Acquired Characters Hereditary? " and in this and 

 in other ways they deal with many matters 

 of extreme interest to naturalists generally. These 

 prints are followed by the reports proper, belonging 

 to the great Hope collection, one for each of the 

 years 1903, 1904, and 1905, occupying together nearly 

 160 pages. They tell a story of expansion, classifi- 

 cation, and orderly rearrangement, all on an extensive 

 scale. It is satisfactory to learn that the very con- 

 siderable work which this entails is making great 

 progress, and that, with the voluntary assistance so 

 liberally given by competent persons in the different 

 departments, the task of overtaking arrears is being 

 rapidly pursued. The time seems not far distant 

 when, notwithstanding the labour involved in dis- 

 posing of the immense numbers of new specimens 

 flowing in from various sources, there will be little 

 wanting and much to approve in the Hope Museum 

 as a reference and self-explanatory collection. Very 

 valuable service has already been rendered by it and 

 its officers and staff as a consulting and educative 

 authority for effective observation by entomologists 

 proceeding abroad. 



Incidentally, many interesting observations find a 

 place in the reports bearing on matters which have 

 recently engaged much attention ; among these refer- 

 ence may be made to illustrations of the extent to 

 which insects are attacked by vertebrate animals, as 

 well as by those predaceous two-winged flies, the 

 .\silids, which successfully attack the stinging 

 Hymenoptera, as well as less formidable victims often 

 much larger than themselves. 



A large part of the report for 1903 is devoted to an 

 account of the work done upon the immense Burchell 

 collection presented in 1866 to the Hope Museum by 

 the sister of the illustrious naturalist, including the 

 pxeparation of a complete and efficient catalogue. In 

 connection with this the interesting story is told of 

 the discovery, as the result of a lecture given by Prof. 

 Poulton at Cape Town, of a portion of Burchell's 

 original journal written in his ox waggon. 



South Africa has been in so many ways disappoint- 

 ing that it is pleasant to find evidence in the " Hope 

 Reports " of its extraordinary value to zoological 

 science. Prof. Ray Lankester, in his recent address 

 as president of the British Association at York, has 

 told us that the study of insects, especially of butter- 

 flies, is one of the most prolific fields in which new 

 facts can be gathered in support of Darwin and new- 

 views tested. It is not, therefore, surprising that many 

 pages of the reports are devoted to butterflies, and to 

 the numerous examples they furnish as to the magni- 

 tude and extraordinary character of the different kinds 

 of variation they present, especially those from South 

 Africa, differences in size, form, colour, and habits 

 between parents and offspring and between offspring 



