294 Miscellaneous. 



ultimate number of toes. This imperfection of a subsequently most 

 important pair of limbs, in contrast with the perfection of a pair 

 which are afterwards much weaker, is doubtless in accordance with 

 the general law, according to which early completion of form limits 

 growth. 



In the anatomy of the adult animal it may be interesting to men- 

 tion the existence of a long but fine ductus Botalli, showing that 

 even before birth the formation of the partitions of the heart arrives 

 at the same completeness as in Placental Mammals. The dissection 

 of the embryo itself was not made, on account of the rarity of the 

 specimen. 



Our investigation of the unborn embryo still in the tuba, when 

 compared with Owen's of the embryo immediately after birth, may 

 make it certain, from the agreement in size and development, that 

 the embryo makes no considerable stay and undergoes no growth 

 and development in the other sexual passages. — Verhandl. des 

 NaturTi. Vereins zu Heidelberg, v. 



On the Oviposition of Mantis reUgiosa. 

 By Edmond Peekiek. 



It has long been known that the ova of Mantis religiosa are en- 

 closed in a case which has sometimes been described as a silky case. 

 In the course of last September I witnessed the oviposition of these 

 insects, and can give an exact account of the process employed by 

 the female Mantis in fabricating her case. 



The material of which this shelter is composed has nothing of the 

 aspect of silk. At the moment when it is ejected it is a frothy 

 liquid very similar in appearance to the frothy liquid with which 

 the larvae of Cercopis surround themselves, but rather less transpa- 

 rent. This matter becomes solidified very quickly, and thus forms 

 for each of the eggs a sort of ceU, in which it remains enclosed. 



To build its case the Mantis employs two instruments — the ex- 

 tremity of its abdomen and the extremity of its elytra. The insect, 

 clinging to the stalk of a broom-plant or of a fern, begins to deposit 

 some portions of its frothy liquid, and sustains them by means of 

 the extremity of its elytra, which form a sort of spoon, at first pre- 

 venting the liquid from flowing downwards, and then constituting 

 an actual natural mould, in which the first layers of the nest are 

 fashioned. Very soon the latter presents a form very similar to that 

 of a swallow's nest. The Mantis then moves the extremity of its 

 abdomen upon the circumference of the nest. The terminal fila- 

 ments are elevated and spread out ; they do not appear to play any 

 very important part in the oviposition. In proportion as the ex- 

 tremity of the body is directed towards a point, the contractions of 

 the abdomen drive on both the frothy liquid and the eggs. The 

 elytra remain motionless, although apiilied pretty strongly to the 

 consolidated part of the nest, upon which we can distingiiish the 

 traces which they have left, which forms a sort of median longitu- 

 dinal ridge. It is evident that by their adhesion to the nest they 



