490 SUMMARY OF CURRENT RESEARCHES RELATING TO 



than a distinct organ ; and the region may extend from around the 

 stomach to the intestine, or may be altogether confined to the latter. 

 He devotes especially attention to the gland embracing the intestine of 

 Microcosmus vulgaris Heller, an interesting organ which seems in many 

 respects comparable to the pancreas of higher vertebrates. 



New Type of Salpa-Chain.* — J. Bonnier and Ch. Perez describe 

 a new form Stephanosalpa polyzona g. et. sp. n. from the Persian Gulf, 

 which has a wreathed chain (chaine en guirlandes) quite different in its 

 architectural arrangement from either the Cyclosalpa or the Salpa type. 



INVEBTEBRATA. 



Mollusca. 

 a. Cephalopoda. 



Structure of Ovary in Cephalopods.f — W. Bergmann describes the 

 ovaries of Sepia, Sepiola, Loligo, and lllex among Decapods, and of 

 Eledone and Octopus among Octopods. The octopod ovary differs essen- 

 tially from that of decapods since the secondary body-cavity in the former 

 is so degenerate that it merely forms a capsule for the gonad- More- 

 over, the octopods have paired oviducts, while the decapods have only 

 one. The author notes, inter alia, that the differentiation of ova or of 

 sex in the gonads of Sepia does not occur early, and that he has observed 

 in Loligo vulgaris a case of binuclear ovum. 



Oxidising Ferments in Ink of Cuttlefishes.^ — C. Gessard finds 

 that cuttlefishes make their ink by a biochemical process similar to that 

 by which the fungus Russula nigricans Bull makes its black. In both 

 there is a ferment — tyrosinase — which acts on tyrosin and produces a 

 black substance. As Bertrand has maintained that tyrosinase in Fungi 

 is always accompanied by laccase, Gessard has sought for the latter in 

 cuttlefishes. He extends Bertrand 's conclusion and finds evidence of 

 yet a third oxidising ferment in connection with the ink-making. 



Nervous System of Nautilus. § — Ch. Gravier has endeavoured to 

 fill some of the gaps in our knowledge of the nervous system of the 

 Pearly Nautilus. He has found, for instance, an anal commissure (sus- 

 pected by Graham Kerr), and he compares it with that in Chitonidse. 

 A very good figure is given. 



y. Gastropoda. 



Locomotion of Slugs. || — K. Kunkel corroborates some of Simroth's 

 observations, e.g. that species of Arion are sluggish and slow in com- 

 parison with species of Limax. He has also made a number of inter- 

 esting experiments, which lead him to the following conclusions. 

 (1) The wave-play lasts for some time in the foot of decapitated slugs, 

 and may be seen even on excised pieces. As Simroth pointed out, this 

 is due to the fact that "the ganglia in the meshwork of the pedal 

 musculature are sympathetic and the wave-play is automatic." (2) When 

 the wave-play has stopped in individual pieces it may be set agoing 



* Comptes Kendus, cxxxvi. (1903) pp. 621-2. 



t Arch. f. Naturges., lxix. (1903) pp. 227-36 (1 pi. and 1 fig.). 



X Comptes Rendus, cxxxvi. (1903) pp. 631-2. 



§ Tom. cit., pp. 618-21 (1 fig.). || Zool. Anzeig., xxvi. (1903) pp. 560-6. 



