1907.] Wheeler, The Polymorphism of Ants. 81 



proved by the production of considerable numbers of males in old and queen- 

 less colonies. In artificial nests Wasmann/ jSIiss Fielde^ and myself have 

 found egg-laying workers in abundance. 



As the males that develop from worker eggs are perfectly normal, and 

 in all probability as capable of mating as those derived from the eggs 

 of queens, we are bound to conclude, especially if we adopt the theory of 

 heredity advocated by AVeismann himself, that the characters of the mother 

 (in this case the worker) may secure representation in the germ-plasm of the 

 species. Weismann is hardly consistent in denying the probability of such 

 representation, for when he is bent on elaborating the imaginary structure of 

 the germ-plasm he makes this substance singularly retentive of alteration by 

 amphimixis, but when he is looking for facts to support the all-sufficiency of 

 natural selection the germ-plasm becomes remarkably difficult of modifica- 

 tion by anything except this eliminative factor. Certainly the simplest and 

 directest method of securing a representation of the worker characters in the 

 germ-plasm would be to get them from the worker itself that has survived in 

 the struggle for existence, rather than through the action of natural selection 

 on fortuitous constellations of determinants in the germ-plasm of the queen. 



If we grant the possibility of a periodical influx of worker germ-plasm 

 into that of the species, the transmission of characters acquired by this caste 

 is no more impossible than it is in other animals, and the social insects 

 should no longer be cited as furnishing conclusive proof of Weismannism. 

 Weismann undoubtedly deserves lasting credit for his accurate distinction of 

 blastogenic and somatogenic characters, and for having rid biological 

 science of a multitude of crude conceptions concerning the inheritance of the 

 latter. Even the many investigators, who, like Boveri,^ Delage,^ Pauly,' 

 Plate,® Rignano,^ and Semon,* still believe in the transmissibility of acquired 

 characters, show the effects of Weismann's clarifying and critical efforts. 



Plate ^ attempts to overcome the difficulties presented by the normal ste- 

 rility of the Avorker by supposing that the distinguishing characters of this 

 caste arose prior to their inability to reproduce. He recognizes the follow- 

 ing stages in the phylogeny of the social insects: 



"1. The presocial stage with but a single kind of male and female. 



1 Parthenogensis bei Ameisen durch Ktinstliche Temperaturverhaitnisse. Biol. Centralbl., 

 XI, 1891, pp. 21-23. 



2 Observations on the Progeny of Virgin Ants. Biol. Bull., IX, 190.5, pp. 355-360; Temper- 

 ature as a Factor in the development of Ants, ibid., IX, 1905. i)p. 361-367. 



3 Die Organismen als Historische Wesen. Wurzburg, 1906. 



* L' H6r6dit6 et les Grands Problemes de la Biologie G6n6ra!e. 2 ed., Paris, C. Reinwald, 

 1903. 



5 Darwinismiis und Lamarckisnnis. MQnchen, Ernest Reinhardt, 1905. 



* Ueber die Bedeutnng des Darwin '.schen Selectionsprincips und Probleme der Artbildung. 

 2 Aufl., Leipzig, Wilh Engelmann, 1903. 



' Sur la Transmissibility des Charact^res Acquis. Paris, Felix Alcan, 1906. 



* Die Mneme als Erhaltendes Prinzip im Wechsel des Organischen Gescliehens. Leipzig, 

 Wilh. Engelmann, 1904. 



* Ueber die Bedeutung des Darwins'schen Selectionsprincips, etc., loc. cil., p. 73-75. 



[January, 1907.] 6 



