830 



SCIENCE. 



[N. S. Vol. XVIII. No. 469. 



had previously been called Zwischenwirbelbein 

 by Von Meyer in Sphetwsaurus, and, long be- 

 fore, Egerton, in 183G, had proposed the phrase 

 ' subvertebral wedge-bone' for the same element 

 in the ichthyosaurs. It may be of interest to 

 observe that Marsh, as early as 1878 (Amer. 

 J own. ScL, May), correctly recognized his 

 ' intercentral bones ' in the so-called liypapo- 

 physes of the Mosasaurs, though Boulenger, as 

 late as 1891, denied their identity. Hypapo- 

 physis is yet frequently used for the inter- 

 centrum of the atlas, following Owen, '-and 

 ' hypocentrum,' ' basiventral bone,' etc., are 

 frequent and superfluous synonyms of inter- 

 centrum. 



There is yet another anatomical term which 

 bids fair to become confused in itsi application 

 — splenial. Owen proposed the term ('Arche- 

 type and Homologies,' p. 15) in place of the 

 Cuverian ' opercular,' a term inadmissible be- 

 cause of its double use in the fishes, for the 

 splint-like element on the inner side of the 

 mandible, and figured as typical of the man- 

 dible in the crocodile and- ostrich. Baur, cor- 

 rectly, I believe, recognizing that the so-called 

 splenial of the turtle is not morphologically 

 identical with the splenial in the crocodile and 

 lizard, but rather a dermal element separated 

 from the articular, gave to it (improperly, 

 I think) the name of angular, while the real 

 angular he called the splenial, and for the real 

 splenial he proposed the new name ' pre- 

 splenial.' Lambe, recently, in his description 

 of the mandibular elements in Dryptosaurus, 

 retains the names previously used in the 

 turtles, but calls the most anterior element, 

 sometimes also present in the turtles, the pre- 

 splenial. But, this is inadmissible. There 

 can be little if any doubt but that the pre- 

 splenial of Dryptosaurus and the testudinates 

 is morphologically identical with the real 

 splenial of the crocodiles and the lizards, and 

 it must receive the same name. If we call 

 it the presplenial, then Baur's arbitrary change 

 of the angular must also be accepted, other- 

 wise the crocodile, to whose mandible the name 

 splenial was originally applied, is juggled out 

 of a splenial entirely ! 



S. W. WiLLISTOX. 



University of Chicago. 



THE OUIGIN OF FEIIALE AND WORKER ANTS FROM 

 TILE EGGS OF PARTHENOGENETIC WORKERS. 



DziERZOx's celebrated theory, according to 

 which the unfertilized eggs of the honey-bee 

 give rise to males, or drones, whereas fertilized 

 eggs develop into females (queens or workers), 

 has not only become one of the established 

 tenets of apiculturists, but has also been ex- 

 panded by theorists to include other social in- 

 sects, such as the ants and social wasps. Nor 

 is this expansion merely the result of a tempt- 

 ing analogy. Forel* and Lubbockf long agO' 

 showed that the eggs of parthenogenetic 

 worker ants may develop into males, and more 

 recently similar observations have been made 

 by Miss Fielde.:j: These facts certainly con- 

 firm the Dzierzon theory and appear to justify 

 its extension to the ants. 



The further question, however, as to whether 

 the unfertilized eggs of bees and ants may not, 

 under certain conditions, give rise to workers, 

 is still unanswered.! In other words, the 

 observation of a number of cases in which 

 males developed from unfertilized eggs, is 

 not in itself sufficient to preclude the pos- 

 sibility of the development of females 

 or workers from such eggs under other cir- 

 cumstances. We know that this possibility 

 is realized in the autumn broods of plant-lice, 

 water-fleas, etc. That it may also be realized 

 in ants is shown by the following observations 

 made independently by three different observ- 

 ers and here quoted as a basis of suggestion 

 for future experimental work. It is, per- 

 haps, timely to stress these observations, for' 

 theorizing on sex determination is much in 

 vogue and is being indulged in by some who 

 seem to derive their facts from any but the 

 original sources. That some of these obser- 

 vations have been ' snowed under ' — todtge- 

 schwiegen, as the Germans say — is not a mat- 

 ter of surprise when we consider the blinding 



'■'' ' Les Fourmis de la Suisse,' 1874, pp. 328, 329., 



t ' Ants, Bees and Wasps,' London. 1S8S, pp. 

 36-40. 



t ' A Study of an Ant,' Proceed. Acad. Nat. Sci. 

 Phila., July, 1901, p. 439. 



§ See also P^rez, ' M^moire sur le Poiite de 

 L'Abeille Heine et la Th^orie de Dzierzon,' Ann. Sc. 

 Nat., G ser., Tome VII., Art. 18, 1878, pp. 1-22. 



