204 SUMMARY OF CURRENT RESEARCHES RELATING TO 



presence of any other bodies, he concludes that the enveloping 

 membrane of frogs' eggs consists of pure mucin. From the oviduct 

 of the frog he also succeeded in extracting a mucin, which though 

 differing from the preceding in centesimal composition, nevertheless 

 agrees with it in all other characters. 



Zoonerythrine and other Animal Pigments.* — C. de Meresch- 

 kowsky gives the results of recent researches on zoonerythrine and 

 other animal pigments. A list of the species in which that naturalist 

 has noted the presence of zoonerythrine includes several members of 

 each of the following, Coelenterata, Echinodermata, Vermes, Crustacea, 

 Bryozoa, Tunicata, Mollusca, and Pisces, in all 117 species. Zoo- 

 nerythrine is usually found in the superficial layer, but in some species 

 it occurs in the muscular tissue. Various phanerogamous and 

 cryptogamoiTS plants also contain it. Numerous other pigments are 

 enumerated. One group of these is characterized by the ease with 

 which they can be transformed into zoonerythrine under the influence 

 of certain chemical or physical conditions, such as elevation to the 

 boiling-point, or the addition of a drop of acid ; while another group 

 is characterized by the impossibility of transforming them into 

 zoonerythrine. 



Commensalism between a Fish and a Medusa.f — Eeferring to G. 

 Lunel's paper J on the union of Caranx and Cramhessa, in which he 

 speaks of the commensalism of fishes and Medusse as something doubt- 

 ful and unknown, W. Macleay points out that the fact was well known to 

 the Commissioners on the Fisheries of New South Wales, who in their 

 report written nearly four years ago, alluding to the Yellow-tail, 

 Trachurus trachurus, say : — " The very young fry have a most extra- 

 ordinary and ingenious way of providing for their safety and nutrition 

 at the same time ; they take up their quarters inside the umbrella of 

 the large Medusae, where they are safe from their enemies, and are, 

 without any exertion on their part, supplied with the minute organ- 

 isms which constitute their food, by the constant current kept up by 

 the action of the curtain-like cilia of the animal." 



B. INVERTEBRATA. 



Annelid Commensal with a Coral.§ — J. W. Fewkes records the 

 fact of an annelid commensal with the coral Mycedium fragile. The 

 worm occupies a calcareous tube, which, for the greater part of its 

 length, is firmly fixed to the lower side of the coral. In a normal 

 coral colony, the tube opens near the edge of the cupuliform disk of 

 the young coral ; the growth of the edge imprisons the worm-tube 

 which, in time, becomes completely surrounded by the living coral. 

 The worm and its tube grow also, and as the tube remains free at its 

 orifice, the worm within is in free communication with the surrounding 



* Bull. Soc. Zool. France, viii. (1883) pp. 81-97. Of. Amer. Natural., xvii. 

 (1883) pp. 1301-2. 



t Abstr. Proc. Linn. Soc. N. S. Wales, 27th December, 1883, p. iii. 



X See this Journal, ante, p. 35. 



§ Amer. Natural., xvii. (1883) pp. 595-7. 



