828 SUMMARY OF CURRENT RESEARCHES RELATING TO 



caeca of star-fishes, &c. The new body would appear to diflfer from 

 plant-chlorophyll in that treatment with nitric acid makes the solu- 

 tion slightly greenish, although previously it may have been yellow. 

 This is explained by the view that the pigment is in a more or less 

 reduced condition, " probably due to the action of a ferment on the 

 chlorophyll, or to the fact that it is sometimes present in the form of 

 a radical or chromogen." 



Spectroscopic measurements show that the liver of the oyster 

 contains a colouring matter which, when treated in alcoholic solution 

 with nitric acid, gives the same spectrum as a similar solution of leaf- 

 green when treated with that reagent. A large number of other 

 Mollusca have been examined. 



Among the Arthropoda, Crustaceans have alone been studied ; in 

 the common crab euterochlorophyll was rarely, but lutein constantly 

 found ; in the crayfish there was abundance of htematin in the 

 bile. 



The pyloric caeca of starfishes were found to function as a so-called 

 liver ; that is to say, they not only seem to prepare a digestive ferment, 

 but they serve as organs for the storing and probably for the actual 

 production of pigments for surface coloration ; enterochlorophyll is 

 here also found. 



Hgemochromogen, which is found in the bile of the crayfish and 

 of the Pulmonate Mollusca, is apparently due to an animal's mode of 

 life, and does not seem to be " distributed according to morphological 

 considerations." 



It is as yet too early to speak definitely, but there is much 

 evidence to show that enterochlorophyll is synthetically formed in 

 the body of its animal possessor. 



The second and third portions of this important paper deal with 

 the Vertebrate bile pigments, and some unusual urine pigments ; the 

 latter should be of interest to the physician as well as to the physio- 

 logist. 



Mollusca. 



Anatomy of the Marine Rhipidoglossa.* — B. Haller here gives 

 bis " first study " on these Mollusca ; treating first of the nervous 

 system and commencing with Fissurella, the author describes four 

 nerve-cords as being given off, on either side, from the oesophageal 

 commissures, viz. the antennary nerves, the cerebro-pedal commissure, 

 the commissure of the anterior visceral ganglia, and the cerebro-pleural 

 commissure. The heart has a double innervation, the auricles and 

 the branchial veins being supplied from the branchial ganglion, while 

 the auricles and the aortas receive their nerves from the abdominal 

 ganglion. The unpaired pedal nerve of Fissurella is shown to be 

 the homologue of the lateral internal pedal nerves found in Haliotis 

 and other forms. The pedal nerves of Haliotis, the form next dealt 

 with, are very long, and are connected together by transverse com- 

 missures ; these are ncjt always equally developed, and it is frequently 

 found that on one side the commissure has two roots, while on the 



* Morphol. Jahib., ix. (1883) pp. 1-98 (7 pis.). 



