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On the other hand, we find that complex eggs alone are present in 

 vast numbers of insects, namely, in all the Lepidoptera, Diptera, 

 Neuroptera (excluding the Libellulidee and allied genera), Hyme- 

 noptera, Hemiptera, Homoptera, and Coleoptera. We are as yet 

 ignorant of the mode of egg-development in the Thripsida and the 

 Strepsiptera ; nor does it seem quite clear whether the development of 

 the pseudovum in Aphis can be referred to the complex type. It 

 would, however, appear from the statements of Leydig, Huxley, and 

 Leuckart, that in the opinion of these three eminent naturalists the 

 pseudovum is a derivation of a single ovarian cell, and differs there- 

 fore in this respect from the ovum of the impregnated female. 



We know little as yet about the early stages of egg-formation in 

 the Crustacea, but it would appear that the simple mode prevails 

 generally throughout this class, with the exception of the Daphnidse, 



As regards the Rotatoria, the so-called winter eggs have been 

 observed in Hydatina, Brachionus, and Notommata, as well as in 

 Lacinularia ; and we may probably conclude that in these and other 

 allied genera the development of these eggs is on the same type ; 

 while " summer eggs" are formed from one cell. Among the 

 Myriapoda, the eggs of Lithobius, Cryptops, Geophilus, Arthrono- 

 malusy Polydesmus, and lulus are simple, the vitelline vesicles 

 occurring in some of them being probably homologous with the yolk 

 nucleus of Spiders. 



Glomeris, however, offers apparently an exception to the rule so 

 general among the Myriapods, as the large rounded bodies present in 

 the egg-capsule are probably homologous with the vitelligenous cells 

 of insects. 



In excluding the ephippial ova of Lacinularia from the category 

 of true eggs, Prof. Huxley was influenced to a certain extent by the 

 supposition that they are fertile without impregnation, and are there- 

 fore " not ova at all in the proper sense, but peculiar buds." Accord- 

 ing to Stein, however, the reverse is probably the case, and the 

 summer eggs are agamic, while the winter eggs require to be fertilized. 

 This is also in accordance with the case of Daphnia. In this genus, 

 as in Rotatoria, the "summer eggs" are agamic, but it has not yet 

 been conclusively proved that the "winter eggs" of either require 

 impregnation. However this may be, the development of the eggs 

 of insects sufficiently proves that eggs composed of several ovarian 



