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SUMMARY OF CURRENT RESEARCHES RELATING TO 
viduals of the same species ( legitime Transplantation ), which readily 
succeeds. A modification of Trembley’s experiment was effected by 
fixing an everted polyp (after removal of head and base) to two normal 
polyps, one at each end. The result corroborated the conclusion 
reached by Engelmann, Nussbaum, and Ischikawa; a polyp cannot live 
permanently in this everted state; but it is not easy to state shortly 
what took place. Union of Hydra grisea and H. fusca was effected 
readily, but the experimenter was not successful with H. viridis and 
either of the others. 
Dactylometra.* — Prof. A. Agassiz and Mr. A. G. Mayer describe 
this genus of Pelagidae. At the present time there are four genera of 
this family known, and they may be distinguished as follows : — 
Pelagia .. .. 8 tentacles .. 16 marginal lappets. 
Chrysaora .... 24 „ .32 „ 
Dactylometra ..40 „ ..48 „ 
Melanaster ..24 „ ..48 „ 
Like other Peiagidse, Dactylometra has eight marginal sense-organs, 
four in the primary, four in the secondary radii — modifications of ten- 
tacles, as L. Agassiz showed. The mouth has four oral fringes or palps. 
There are sixteen simple pockets round the stomach, eight leading out 
into the sense-organs, eight others into the tentacles. The genital 
products are contained in four radially situated infoldings of the oral 
wall of the stomach, and their position is marked upon the oral floor of 
the disc itself by four deeply sunken sub-genital pits. The genital 
organs are further furnished with numerous gastric cirri, which project 
inwards into the cavity of the stomach. The authors give a general 
account of the structure and habits, and the illustrative plates are of 
unusual excellence. 
Keeping Medusae alive. | — Mr. E. T. Browne finds that the secret 
of keeping Medusae alive in an aquarium is to have the water in motion, 
so that the animals can float about just as they do in the sea, without 
having constantly to pulsate the umbrella. The intervals of floating are 
periods of rest. He succeeded by a simple device in keeping a glass 
plate moving up and down, fairly slowly, inside a bell-jar. This 
“plunger” arrangement, as he calls it, proved very effective. Thus, to 
quote one result, three dozen unselected Medusae were placed in a bell- 
jar holding about two gallons, and given a good supply of copepods. 
They were left untouched for ten days, except that copepods were added 
when the supply became low, and at the end of this period thirty-one 
were alive, and more than half of them in excellent condition. 
Cubomedusse.J — The late Dr. F. S. Conant, one of the victims of the 
Jamaica expedition, had finished before his death a memoir on the 
structure of the Cubomedusae, which has been published by his friends, 
along with a short biographical notice. 
The Cubomedusae are of more than passing interest among jelly- 
fish, both because of their comparative rarity, and because of the high 
* Ball. Mus. Comp. Zool. Harvard, xxxii. (1898) pp. 1-11 (13 pis.). 
t Journ. Mar. Biol. Ass., v. (1898) pp. 176-80 (1 fig.). 
t Mem. Biol. Lab. Johns Hopkins Univ., iv. (189«) xvi. and 61 pp. (8 pis. and 
1 fig.). 
