ZOOLOGY AND BOTANY, MICROSCOPY, ETC. <;07 



twenty-six nerves, while the solitary form of S. henseni, which is weakly 

 muscular, has fifty-five nerves. 



The innervation of the luminescent organs has been clearly proved. 

 Nerves pass to the ingestive, egestive, and somatic musculature, to the 

 endostyle, and to the olfactory organ. Anastomoses are characteristic of 

 S. pinnata, crossings of the aggregate form of S. confmlerata, and of the 

 solitary form of S. zonaria. Otherwise, the nerves of Salps seem to have 

 a simple course with few branches. The nerves may be arranged in six 

 groups : a dorsal group to the ingestion aperture and the olfactory 

 organ ; a dorsal group to the egestion aperture ; a ventral group to the 

 egestion aperture and the body musculature ; strong nerves to the 

 ciliated band, the luminescent organ, the " Bogen " muscle, and the 

 endostyle ; and lateral nerves to the body muscles, the luminescent 

 organs, and the endostyle. 



Luminous Cells of Pyrosoma and Salps.*— Ch. Julin calls atten- 

 tion to the specificity of the " luminous cells " of Pi/rosoma (jiganteum 

 and Cydosalpa pinnata. In the lateral organs of the Salp there are 

 cells with a remarkable intra-cytoplasmic coil just like the luminescent 

 cells of Pyrosoma. In the Salp the lateral organs are haematopoietic as 

 well as luminescent, and there are blood-cells at various stages of 

 development. In Pyrosoma the two functions are separated ; the 

 luminescence has its seat in the organ of Panceri, the blood-making in 

 the dorsal organ or gland which is lodged in the dorsal sinus of the 

 branchial sac. 



INVERTEBRATA. 



Molluscs. 



«• Cephalopoda. 



Nervous System of Sepia.f — R. Hellig has made an intimate study 

 of the ganglia and nerves of Sepia officinalis. The central nervous 

 system is composed of cerebral, visceral, pedal, and brachial ganglia, to 

 which the upper and lower buccals must be added. In the order 

 named, these ganglia give off four, seven, five, four, several, and four 

 nerves, which are described in detail and finely figured. 



S. Lamellibranchiata. 



Gonads of Oysters. | — J. L. Dantan finds that in one reproductive 

 period about half of the oysters {Ostrea edulis) produce spermatozoa 

 only, while the others produce first spermatozoa and then ova, or first 

 ova and then spermatozoa. " Male " oysters are always in a great 

 majority. In the Portuguese oyster, Gryphsea angulata, the sexes are 

 separate, and females are always in the majority. 



* Comptes Rendus, civ. (1912) pp. 525-7. 



t Zeitschr. wiss. Zool., c. (1912) pp. 736-800 (3 pis. and 9 figs.). 



J Comptes Rendus, civ. (1912) pp. 324-7. 



