OCR Text |
Show 916 ON REGENERATION OF THE LEGS IN THE BLATTID.E. [Nov. 30, cuticle remains adhering to the hinder end of the abdomen for more than a day after. Coloration of the new cuticle commences as blotches on the dorsal surface and extends gradually to the outlying parts, the extremities of the limbs becoming completely coloured by the end of the third day after ecdysis. The animal remains unusually still during this period and eats very little, apparently not at all during the first clay. Loss of Appendages during Ecdysis.-Bive cases were observed in which normal, and apparently uninjured, tarsi were broken off during ecdysis. This may result from a struggle to free the leg during its sliding away from inside the old cuticle. As already pointed out, the region where a break in the leg occurs most easily is the suture between the femur and trochanter, so that these occurrences of a break at a normally stronger point may perhaps be accepted as an indirect argument that there is a certain degree of autotomy in the usual rupture between femur and trochanter. Note on, the Numerical Proportion of the Sexes. Among the whole number of adult specimens collected for the purposes of the present enquiry, the actual and percentage distribution of the sexes were :- P. australasice Male. 371 118 47 505 49*5% 51*3% 46-1% 30-9% Female. 379 112 55 1130 50-5°/o 48-7°/0 53*9% 69*1% As the habits of the two sexes are similar, the above is probably a fairly accurate indication of their usual numerical proportion, except possibly in the case of Phyllodromla germanlca. In a future communication I hope to give an account of the structure of the reproduced leg with special reference to the four-jointed tarsus, and also of certain cases in which apparently reproduced tarsi were found to be in a three-jointed condition. |