THE PHYLOGENY OF THE TERMITES. 33 



pared with that of the incipient germ-band, the position of the 

 latter on the posterior ventral surface of the egg, the pro- 

 nounced anatreptic and katatreptic movements of the embryo, 

 etc. Comparison of the termite with the Blattid shows great 

 similarity in the structure of the micropyles, but, as I have 

 pointed out ('89, '93), the blastokinetic, or embryonic movements 

 in the latter insect are very feeble, not sufficient, in fact, to carry 

 the embryo from the anterior to the posterior surface of the yolk. 

 This slight movement I interpreted as a vestige of the more pro- 

 nounced blastokinesis of the Saltatoria. If this view is correct, 

 we must suppose the Termitidae to have retained in the more 

 pronounced movements of the germ-band somewhat more prim- 

 itive orthopteroid conditions than the Gressoria (Blattidae and 

 Mantidae). This is, of course, not necessarily fatal to a deriva- 

 tion of the termites from the Blattidae, since a modification of 

 the embryonic development in the direction of a partial suppres- 

 sion of blastokinesis may have supervened within the Blattid 

 group after the Termitidae had diverged from the more primitive 

 family stock. 1 



At first blush there would seem to be no ethological relation- 

 ship between the Blattidae and the Termitidse. The former are 

 regarded as omnivorous insects without a social organization 

 whereas the latter have a specialized diet of cellulose and present 

 a social organization only equalled or surpassed in complexity 

 by that of the ants, certain wasps and bees. Somewhat closer 



1 Knower seems to have misunderstood my position in regard to the superficial and 

 immersed germ-bands of insects. At any rate his long discussion of this and kindred 

 matters tends only to befog the whole subject. I expressly maintained ('93, p. 68) 

 that the stationary, superficial germ-band is primitive in the Arthropoda in general, 

 and probably also in the insects in particular, but that in the latter class blastokinesis, 

 with or without immersion, early established itself since it is found in many primitive 

 orders. Later these movements were abolished (the Blattidas, e. g., show them very 

 feebly), so that the higher insects (Coleoptera, Hymenoptera, Diptera, etc.) have 

 secondarily returned to the primitive type of an almost stationary, superficial germ- 

 band. I believe the chief stress in these considerations is to be laid on the move- 

 ments of the embryo and not on the more incidental superficiality or immersion of the 

 embryo. Whether embryos like those in Knower' s stages M and N (PI. 33) are to 

 be regarded as superficial or immersed is open to serious doubt. A form like the 

 locustid Xiphidium is immersed during anatrepsis, but superficial during katatrepsis. 

 In passing I may express my inability to conceive why Knower courts confusion by 

 inverting all the figures of his termite embryos. 



