ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 609 



degree of differentiation. In the Camponotinge it is quite rudimentary, 

 serving only as a support for the efferent duct of the poison-bladder, 

 which produces in this case a large quantity of poison. Some of these 

 ants can squirt out the poison to a considerable distance. In another 

 group, the Dolichoderinaj, the sting is like a functional sting in appear- 

 ance, but it is weak and without a well-developed point. There are 

 transitions between the well-developed stings of Myrmicina?, Ponerinse, 

 and Doryhnte, and the reduced sting of the Dolichoderinas, but the quite 

 rudimentary apparatus of the Camponotinte stands isolated. 



Foerster finds an interesting specific diversity in the form and size of 

 the parts of the sting in the Myrmicin^ and other forms in which it is 

 well developed. He also finds that there are various grades of rudimentari- 

 ness in the Camponotin^, where it is best developed in some species of 

 Formica {F. rufa, F. p?-atensis, F. trimcicola, and F. sanguined) ; weaker 

 in Polyeryiis and Camponotus ; most reduced in Plagioleins lyygmd&a and 

 Lasius. In the Myrmycinte and Dolichoderinfe examined, the stings of 

 queens and workers were the same. A striking difference between the 

 sting of queen and worker was observed in Formica, and less markedly 

 in Polgergus. 



Respiratory Apparatus of Insect Ovary.* — E. Riede has made a 

 detailed study of the stigmata and tracheae in connexion with the ovaries 

 in the various classes of Insects. There is a great diversity. In fact, 

 the only uniform feature is that the oviducts receive their tracheae from 

 the last abdominal stigma. In some cases all the abdominal stigmata 

 send trachea3 to the ovarioles ; usually the middle set of stigmata 

 (especially -i and 5) are concerned. In Lepidoptera all the abdominal 

 stigmata, except the first two, send some main branches to the ovarioles. 

 In contrast to this is the condition in some Hemiptera, where tracheae 

 go to the ovary from one stigma only. 



The tracheae never penetrate into the ovarian tubes. They remain 

 always in the external connective tissue, the so-called peritoneal envelope. 

 In some cases the peritoneal envelope is very richly supplied with fine 

 branches of the tracheas, and the blood is unimportant as an oxygen 

 carrier. In other cases there are very few tracheal capillaries in the 

 peritoneal envelope, and the blood is important. An ovarian circulation 

 is secured in these cases in various ways, by the muscularis of the peri- 

 toneal envelope, the movements of the ovarioles, a specialization of the 

 pericardial septum, and the ventral septum which serves as a true 

 circulatory organ. 



Study of Boring Beetle.f — F. C4ermer has made a study of Hylecatus 

 dermestoides and some other Lymexylonidte. In the species named the 

 males are distinguished by much modified and richly innervated maxillary 

 palps, which form a smelling organ chiefly useftil in finding the female. 

 If the palps are removed, no copulation occurs. The imagines are short- 

 lived, and do not eat ; the larvaB remain larval for more than a year, and 



* Zool. Jahrb., xxxii. (1912) pp. 231-310 (3 pis. and 10 figs.), 

 t Zeitschr. wiss. Zool., c. (1912) pp. 683-736 (2 pis. and 31 figs.). 



December 18th, 1912 2 T 



