ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 739 



eating ; (6) forces antagonistic to the preceding ; (c) propulsive, flexing 

 and depressing the anterior plane ; and (d) forces which depress and 

 propel the posterior plane. The first two of these are inserted into 

 the roof and floor, the last two into the base of the wing. The motor 

 forces are the voluntary muscles, the actions of which are combined 

 with involuntary, that is, elastic forces : of the latter, the chief are 

 the resistance of the roof to the curvature caused by the former when 

 the wing is depressed, and the resistance of the anterior part of the 

 point of support to the flexion due to the muscles of group (c). 



The author bases these conclusions on what he has seen in the 

 Orthoptera, Pseudo-neuroptera, and Hymenoptera. 



Poison of the Hymenoptera and its Secreting Organs.* — G. 

 Carlet, in opposition to j)revious observers, finds that the venom- 

 producing apparatus of the Hymenoptera is always formed by two 

 distinct systems of glands, one of which has a secretion which is 

 strongly acid, and the other feebly alkaline. The two systems open 

 at the base of the spine, and the combined liquid is always acid. 

 Experiments made on the common house-fly showed that the sting of 

 a venomous Hymenopteron was always followed by the immediate 

 death of the fly, but that the inoculation of the product of either of 

 the glands does not result in death, or only in death after a long 

 interval. The successive inoculation of the two secretions leads to 

 death shortly after the second inoculation, and we may suppose that 

 life ceases as soon as the two liquids have mixed. It is then clear 

 that the union of the acid and alkaline secretions is necessary for the 

 venom to have any fatal eff'ects. 



Development of Cerocoma Schreberi and Stenoria apicalis.t — 

 H. Beauregard communicates some facts as to the development of 

 certain insects allied to Cantharis ; the larvas appear to be melli- 

 vorous, and it is possible that they may live as parasites indifferently 

 in certain Hymenoptera. The larvfe, contrary to the habits of Epi- 

 canta and Macrobasis, as described by Eiley, do not live on the eggs 

 of Orthoptera. It has been found that the larva of Cerocoma lives on 

 the honey of Colletes and of Osmia. 



Other pseudochrysalids found in the cells of Colletes signata, and 

 presenting a very regular ovoid form, of a golden yellow colour, and 

 enveloped in a very fine iridescent pellicle, were watched through 

 the winter, and found in May to commence to undergo a series of 

 metamorphoses which ended in the appearance of the adult Stenoria 

 apicalis, which was found by Lichtenstein to be, in its earliest stages, 

 parasitic on Colletes fodiens. Here, again, therefore, we have evidence 

 as to the indiff"erence which these parasites exhibit as to their choice 

 of a host. The history of development justifies the separation of 

 Stenoria from the true Sitaris. 



Dipterous Larvae.:}: — Dr. F. Brauer has published a valuable mono- 

 graph on this suVjject, the result of ten years' labour. 



* Comptes Rendus, xcviii. (1884) pp. 1550-1. 

 t Ibid., xcix. (1884) pp. 148-51. 



X Denkechr. K. Akad. Wiss. Wien, xlvii. (1883) 100 pp. (5 pla.). Cf. Amcr 

 Natural, xviii. (1884) pp. 609-11. 



