384 SUMMARY OF CURRENT RESEARCHES RELATING TO 



caecum : and these caeca were mixed up with those containing larvas of 

 females. The development of the male larva was traced to the perfect 

 state ; when it is characterized by its small size, thin integument, absence 

 of eyes and of wings, and by the development of spermatozoa before the 

 appearance of the appendages. 



The development of the spermatozoa differs considerably from that in 

 neighbouring forms. 



Although doubtful on the point, M. Moniez considers it probable that 

 impregnation takes place while the male is still within the female : and he 

 shows how, by a farther reduction of the male, till it is represented by only 

 sexual elements, a false hermaphroditism may be brought about. Thus, 

 many cases of parthenogenesis and paedogenesis may really be gamogenetic, 

 since the pseudova may be ordinary ova, fertilized before being laid, by 

 means of the spermatozoa, which are all that represents the male. 



Galls on the Leaf of the Vine.* — Herr T. von Ohrdruf states that on 

 the leaves of vines, cultivated in Europe, three kinds of galls can be 

 distinguished : — (1) The Erineum of Phytontus Vitis, (2) the Phylloxera 

 gall, and (3) the gall of Cecidomyia cenopliila. 



The Erineum cannot be confounded with the other two ; but in order 

 to distinguish the two latter, the following characters are given. The galls 

 of Cecidomyia project from both surfaces of the leaf, are circular in form, 

 and their colour varies from greenish yellow to deep red. They are spread 

 over the leaf without any order, and their number is sometimes as many 

 as from thirty to sixty. The Phylloxera galls are of the same shape, the 

 difference, however, is that these galls on the upper surface of the leaf have 

 a roundish or fissure-like opening, bordered by hairs and projections, while 

 on the under surface of the leaf there is a large projection with a contraction 

 at its base. The gall of Cecidomyia has no opening on the upper surface, 

 is small, and lenticular in form. 



B. Myriopoda. 



Ancestors of Insects, j — Dr. E. Haase thinks that Scolopendrella stands 

 nearest to the primitive insect or Archentomon ; it is distinguished by its 

 multiarticulate antennae ; three pairs of jaws, of which the last is poorly 

 developed, its twelve pairs of five-jointed ambulatory legs, and a pair of long 

 caudal appendages in which is placed a spinning-gland. It is also remark- 

 able for its abdominal processes ; these appear to correspond morpho- 

 logically to the calcaria of most Tracheata, and are homologous with tho 

 appendages on the last two pairs of legs in Macliilis ; from the second to 

 the eleventh segment there are clefts leading to pouch-like glands, which 

 may be distinguished as the abdominal pouches ; these obtain also in most 

 of the Thysanura, in Peripatus, and some Myriopoda. The evidence 

 afforded by larvae of insects is also discussed, and some of the difficulties 

 explained by supposing that separate developmental phases which appeared 

 successively are compressed and intercalated with one another in the course 

 of ontogenetic development. The wings may be regarded as folds of the 

 dorsal plate. 



Relationships of Myriopods.f — Starting from Scolopendrella, Dr. E. 

 Haase seeks to derive from a related type the orders of Myriopods and of 

 apterygota or lowest insects. He lays emphasis on the morphological 



* Entom. Nachr., 1886, pp. 129-35. See Bull. Soc, Bot. France, viii. (1886), Kev. 

 Bibl., p. 219. 



t SB. unci Abliaiull. Isis in Dresden, 18cS6 (1887) pp. 85-91. 



X Biol. Centralbl., vi. (1887) pp. 759-00. (Bur. Versammlg. Naturf. u. Aerzte 

 Berlin, 1886.) 



