ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 713 



did not seem to be affected, but as the embryo began to assume a 

 cordiform shape, the influence made itself felt. The cells became dis- 

 ordered and ruptured outwards. The primordia became unrecognisable. 

 Cells were set adrift. The deformed larva' all died without being 

 hatched. 



New Brazilian Opisthobranchs.*— F. M. MacFarland describes the 

 following new species : Pleurobranchus agassizii, Discodoris branneri, 

 D. voniheringi, Peltodoris greeleyi, and Spurilla braziliana, and also gives 

 a full account of Tethys dactylomela Rang, and T. cervina Dall and 

 Simpson. Particular attention is given to the nervous systems. 



Arthropoda. 

 o. Insecta. 



Accessory Genital Organs in Female Cockroach.f — L. Bordas 

 describes in detail the left arborescent gland, which makes lime for the 

 ootheca, the right arborescent gland, which makes a mucilage used in 

 fixing the ootheca to some external object, and the spermotheca which 

 consists of two tubes very unequal in size. 



Thoracic Sclerites of Insects.^ — Gr. C. Crampton makes an im- 

 portant contribution to the comparative morphology of the thoracic 

 sclerites in insects. These sclerites are much used in classification and 

 myology, but there is a confusing lack of uniformity in the terminology 

 employed and as to the homologies recognised. The comparative 

 morphological study which Crampton has made is very Avelcome. 



Burrowing Wasp Destructive of Glossina.§ — F. Picard gives some 

 account of a species of Oxybelus, which hunts the tsetse fly (Glossina 

 palpalis) in Senegal and Nigeria. 



Spermatogenesis in Acrididse and Locustida3.|| — H. S. Davis has 

 made an investigation of the spermatogenesis in these two families of 

 the Orthoptera, His paper gives a full account of spermatogenesis in 

 Dissosteira Carolina, with notes on points of special interest in six other 

 species studied. His results are as follows : In all the forms studied 

 there is a single apical cell of characteristic appearance at the distal end 

 of each follicle. The primary spermatogonia surround and are in 

 contact with the apical cell. The secondary spermatogonia are enclosed 

 within a membrane formed by connective-tissue cells, the whole con- 

 stituting a sperinatocyst. All the spermatogonia in each cyst are the 

 direct descendants of a single spermatogonium, which become surrounded 

 by one or more connective-tissue cells, and are, with rare exceptions, at 

 practically the same stage of development. 



The resting nuclei of the spermatogonia vary greatly in shape, and 

 show a marked depression on the side adjacent to the greatest amount 



* Leland Stanford Junior Univ. Publications, University Series, No. 2 (1909) 

 105 pp., (19 pis.). 



t Ann. Sci. Nat., ix. (1909) pp. 71-121 (1 pi., 18 figs.). 



% Prac. Acad. Nat. Sci. Philadelphia, lxi. (1909) pp. 3-54 ( 4 pis. and 21 figs.). 



§ C.R. Soc. Biol. Paris, lxvii. (1909) pp. 360-2. 



|| Bull. Mus. Comp. Zool. Harvard, liii. (1908) pp. 59-158 (9 pis.). 



