ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 525 



the glandular scales sometimes have sensory cells. As to the function 

 of the sensitive scales, we may exclude the possibility of an olfactory 

 function, for the nerve does not enter the scale, and there is no com- 

 munication with the outer world. But are they auditory, or gustatory, 

 or like the nerve-endings on bats' wings ? Here experiment must come 

 to the aid of histology. 



External Sexual Organs in Male Lepidoptera.* — L. Poljanec finds 

 that the last three segments of the abdomen (segments 8, 9, 10) may 

 be modified in connection with reproduction in male butterflies. In 

 neotropical forms apophyses occur both on tergite and sternite of the 

 eighth segment, and two rami on the posterior border of the sternite. 

 The ninth segment bears outgrowths to which the name of sacci i& 

 given, and also at its posterior border tbe outer valvse, which are often 

 asymmetrical. In some species inner valvas are present, corresponding 

 to the gonapophyses of other insects. Where the tenth segment is. 

 complete, it has the form of a bird's bill ; its sternite exhibits a ten- 

 dency to bend over in a dorsal and postanal direction. This segment 

 bears traces of a telson. The penis is chitinous almost throughout, and 

 is surrounded by a penis-armature. The external genital organs are 

 usually furnished with hairs and bristles, which may be connected with 

 nerve-endings. 



Structure of Adult Female Mosquito.f — Dr. S. E. Christophers 

 has studied the minute structure of Culex and Anopheles. In the ali- 

 mentary canal the proventriculus of other insects is absent, but a fold 

 occurs at the origin of the mid-gut which is undoubtedly its homologue. 

 It consists of both ectoderm and endoderm, but is without chitin, and 

 appears only to act as a muscular sphincter. In Culex the salivary 

 glands are tubular, while in Anopheles they are sacculated. In both 

 cases there are two types of gland acinus, the granular type and the 

 clear or colloid-like type. Very little change in the glands occurs 

 after feeding, a large amount of secretion remaining within the gland. 

 The ova in Anopheles frequently contain a mass of Sporozoa. 



Spermatogenesis in Staphylinus.f — Nils Holmgren sums up the 

 most important results of his study of spermatogenesis in this beetle. 

 In winter in the adult Staphylinus there is a regeneration of spermato- 

 genic elements from the cells of the testicular capsule. Verson's cell 

 occurs in Coleoptera. The formed spermatogonia are of two entirely 

 different sorts. There are two quite distinct series of spermatozoa. 

 Old spermatozoa are normally destroyed by the activity of their cyst- 

 cells, and undergo fatty degeneration. The fat accumulated in the 

 cyst-cells serves for the nourishment of newly formed spermatozoa. 



Development of Male Genitalia in Scolytidae. § — L. Schroder 

 briefly summarises the results of his researches on this subject. He 

 finds that the first rudiment of the sexual ducts is a paired structure 

 of mesodermic origin, which grows towards the end of the abdomen. 



" Arbeit. Zool. Inst. Wien, xiii. (1901) pp. 155-96 (3 pis. and 5 figs.). 



t Reports to Malaria Committee of Roy. Soc. Lond., iv. (1901) pp. 1-20 (6 pis.). 



J Anat. Anzeig., xix. (1901) pp. 449-61 (5 figs.). 



§ Zool. Anzeig., xxiv. (1901) pp. 460-1. 



