ZOOLOGY AND BOTANY^ MICROSCOPY, ETC. 725 



alter it ; as it empties it is filled by aspiration. This reservoir is only 

 found in the Mellifera, where it is necessarily correlated with the 

 perforation syringe which forms the stinging apparatus of these Insects, 



Morphology of the Legs of Hymenoptera.* — Prof. A. J. Cook dis- 

 cusses some points in the morphology of the legs of hymenopterous 

 insects. He begins with the prothoracic legs of the honey-bee, and 

 traces the modifications of the "antenna cleaner" throughout a series of 

 forms. From the study of this organ alone (so persistent is the type 

 within each family) the species of Hymenoptera might, with very few 

 exceptions, be arranged in their respective families. The discussion of 

 this apparatus in its details and varied occurrence forms the greater part 

 of the paper. 



Salivary G-lands of Cockroach.f — Herr Bruno Hofer has made an 

 intimate investigation of the structure of the salivary glands in Blatta 

 and of the nature of the associated nervous arrangements. 



(a) The general structure and mechanism of the glands is first de- 

 described. Special attention is directed to the paired muscle passing 

 from the under side of the oesophagus to the gland, and probably in part 

 contracting the reservoir and accommodating the gland to the movements 

 of the body. In jB. germanica there is another muscle from the posterior 

 end of the reservoir, which it probably serves to empty. Any connection 

 of the salivary duct with the oesophagus is excluded by the interposition 

 of the very massive hypopharynx. The duct opens between hypophysis 

 and under lip, to the outer walls of which it is completely fused. 



(&) The histology of the glands is next discussed. The formation of 

 the secretion is apparently as follows : — In the fine protoplasmic threads 

 of the unencapsuled cells, fine glancing secretion-granules appear ; these 

 become more numerous, form larger spherules, and replace the proto- 

 plasm ; these granules must then in some way (probably by a water- 

 stream) become soluble and diff'use into the capsules and ducts ; the 

 secretion passes from capsules to ducts, and thence into the reservoir ; 

 at the same time the unencapsuled glandular cells re-exhibit fine proto- 

 plasmic threads extending from their margin into the lumen of the gland. 



The second chapter of the memoir deals with the nervous apparatus. 

 Herr Hofer first discusses the unpaired and paired visceral nervous system, 

 and describes the distribution and histology of the nerves. They have a 

 double function, serving as a centre for the peristalsis of the oesophagus, 

 and forming the innervation of the salivary glands. Passing to the 

 more intricate question of the exact connection between nerves and 

 glands, the author confirms the correctness of Kupffer's observation that 

 the nerves do really penetrate iuto the glandular cells. He completes 

 it in the more detailed observation that several nerve-fibrils fuse with 

 the striated protoplasm of the encapsuled glandular cells, but do not 

 exhibit any peculiar terminations. 



Parthenogenesis in Bombyx mori.l — Prof. A. TichomirofP urges 

 that both well-known and recent observations confirm the statement 

 that true parthenogenesis does occur in Bombyx mori, though it has been 

 recently doubted by Prof. Verson.§ 



* Amer. Natural., xsii. (1888) pp. 193-201 (10 figs.). 



t Nova Acta Acad. Ca^s. Leop.-Carol., li. (1887) pp. 349-95 (3 pis.). 



X Zool. Anzcig., xi. (1888) pp. 342-4. § See this Journal, ante, p. 571. 



1888. 3 D 



