384 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Arthropoda. 

 a. Insecta. 



Haemolymph of Insects.* — Kurt Geyer has made an elaborate study 

 of the haemolymph, with especial reference to caterpillars and pupae. 

 A sexual difference is frequent, that of the females being green and 

 that of the males bright yellow to colourless. In the female's haemo- 

 lymph there is slightly altered chlorophyll ; in the male's there is xan- 

 thophyll or no pigment of this sort. As the result of many castration-, 

 transplantation-, and transfusion-experiments, the author concludes that 

 in insects the entire soma is sexually differentiated as respectively mascu- 

 line or feminine. The influence of gonadial hormones varies in different 

 types, according to the strength of the primary sexual differentiation of 

 the soma. 



Enigmatical Peri-oesophageal Organ in Tineidge.f — A. Hufnagel 



describes in GracuJarIa syringella and Hyponomeuta padella a peculiar 

 organ around the gullet in the region of the neck. It is a syncytial 

 ring, with scattered nuclei and ill-defined cell limits. Its elements 

 may be oesophageal cells which have migrated into the cavity of the 

 body. They appear in the larva ; multiply by karyokinesis till the 

 beginning of the third day of pupal life ; two lateral masses unite in a 

 ring ; the nuclei l^ecome irregular and lobed — the imaginal condition. 



Spermatogenesis in Silk-moth. J — Naohide Yatsu has compared the 

 spermatogenesis of the wild silkworm {Theophila mandriana) and of 

 seventeen Japanese and other races of the domesticated Bombyx mori. 

 He found that all the chromosomes look almost alike, there being no 

 apparent correlation between external features and chromosomes. The 

 haploid number of chromosomes in the domesticated silkworm is twenty- 

 eight, contrary to Toyama's statement. In tJie wild form the haploid 

 number of chromosomes is twenty-seven. If the wild form is ancestral 

 to the domesticated form, two additional chromosomes have been gained. 

 But when and how these two came into existence is still an open question. 

 Not unlikely ancient people took hold of a mutant from the wild 

 Theopliila and succeeded in producing from it the races better fitted for 

 their need. 



Nuclear Structure in Salivary Glands of Chironomous Larvae. § 

 W. Faussek describes the minutiae of nuclear structure. Within the 

 definite membrane there is a nucleolus, or there may be two, and there 

 is the nuclear filament. The nucleolus consists of an internal and more 

 compact basichromatin, and an external oxychromatin which includes 

 granules of basophilous substance. Similarly, the nuclear filament con- 

 sists of basophilous granules in an oxyphilous matrix. The basophilous 

 granules are concentrated in transverse disks, which build up the 

 filament. 



* Zeitschr. wiss. ZooL, cv. (1913) pp. 349-499 (8 pis. and 58 figs.). 



t Comptes Rendus, clvi. (1913) pp. 1636-8. 



X Annot. Zool. Japon., viii. (1913) pp. 215-20 (8 figs.). 



§ Arch. Mikr. Anat,, ixxxii. (1913) Abt. 1, pp. 39-60 (2 pL). 



