ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 189 



the results obtained in regard to the inheritance of the genital spot 

 which marks E. rariolariuf . The study of this second exclusively 

 male character supports in every detail the conclusions of the previous 

 investigation. The results are out of harmony with the chromosome 

 hypothesis of sex-determination and with the recent hypotheses 

 of chromosome-distribution of unit-factors. 



Histolysis during Regeneration of Appendages in Certain 

 Orthoptera.* — E. Bordage calls attention to a process of histolysis he 

 has observed in studying the regeneration of the appendages of certain 

 Orthoptera. Phagocytosis plays only a subordinate part in the dis- 

 appearance of the old muscles ; it is chiefly brought al)out by a special 

 process of fatty degeneration giving rise to adipose flocculi and 

 strands similar to those of normal adipose tissue. Sometimes the adipose 

 tissue arising from the transformation of muscular tissue takes very 

 irregular contours, at other times it takes the form of a network with 

 very large meshes. All stages of transition between these forms have 

 been observed, especially in Mantids. Since this process of histolysis 

 and histogenesis sets in only during a moult, when the animal is 

 motionless, and is not only not feeding, but is drawing upon its normal 

 adipose tissue, the author is led to conclude that this special tissue is of 

 purely internal origin, and is the result of a histolysis of the old tissue, 

 especially the muscle. The luiclei of the adipose tissue arising in this 

 way are the nuclei of the old tissue, modified in form and increased in 

 volume. The transformation is prol)ably due to an enzyme, apparently 

 contained in the pre-existing or primary adipose tissue, for it is observed 

 that transformation begins at the points where the muscles that are to 

 disappear are in contact w' ith the primary adipose tissue. The secondary 

 tissue has a brief life, and soon gives place to the new muscle of the 

 regenerated appendages. Whether phagocytosis aids in its disappear- 

 ance has not yet been established. 



New Lice.t — Bruce F. Cummings describes two new species, Po/z/- 

 pUfx hrachyrriiijaclms and P. oxyrrhyndi/iis, of which large numbers, in 

 different stages, were collected in Egypt from Acomys cahirinus, one of 

 the Muridse. A third form, P. spkmlosa, is also discussed for com- 

 parison. An examination of the immature forms in these three species 

 shows that the metamorphosis includes at least three distinct stages, 

 although there may be more than two moults. The differences between 

 Stages II and III are slight. In the first stage the louse is very soft 

 and delicate, but even thus early the mouth-parts, thorax and legs 

 are well chitinized. On the abdomen segmentation is absent except 

 at the end, and sclerites are absent in all three stages, although in 

 P. QxyrrhyncJius and P. spmidosa minute pleurites appear in Scage II, 

 and in Stage III of P. hrachyrrhynrJiu.'t also there are present weak 

 pleurites of indefinite outline. The spiracles are large. In the last 

 stage the head and thorax closely resemble the adult. 



In all three stages the chjetotaxy of the head and thorax is almost 



* Comptes Rendus, clxi. (1915) pp. 155-9 (1 fig.). 

 t Proc. Zool. Soc, 1915, pp. 245-72 (16 figs.). 



