OPERATIONS AT THE LABORATORY. 
519 
schooner Grampus to the Gulf Stream to obtain data respecting the 
existence of the tile-fish, which was so mysteriously destroyed in such 
inconceivably vast numbers a few years since. While the search for 
tile fish again proved fruitless, collections of Salpa , heteropods, ptero- 
pods, and Sagitta were obtained in fine condition, besides several well- 
preserved Physalice and Discomedusm. 
During these expeditions Dr. Brooks also experimented very success- 
fully with entirely new methods of preserving such delicate organisms 
as jelly fishes. The method, which is a very simple one, consists in 
adding glycerine to Pereuyi’s fluid until a solution is obtained of the 
specific gravity of sea water. In this the jelly-fish is killed. The speci- 
men, after the killing is completed, is transferred to a mixture of alcohol 
and glycerin of the same specific gravity as the first ; in this it is pre- 
served, and remains flexibly transparent and preserves its form as well 
as its histological structure admirably. The results so far obtained 
show that the method will be a most useful and convenient one. 
A complete series of the early stages of the small viviparous lamelli- 
branch, Sphcerium sphericum , was also obtained by Dr. Brooks from the 
fresh-water pools in the vicinity of Wood’s Holl. Some interesting facts 
regarding the manner in which the young mollusk is nourished by and 
inclosed in capsules between the gills of the parent have been obtained 
by Dr. Brooks from the preliminary study of these animals. 
Workers from other institutions have also availed themselves of the 
facilities afforded by the station for the collection of materials for class 
work. Among those who have been there for that purpose are Prof. 
S. F. Clarke, of Williams College ; Prof. J. S. Kingsley, of the Indiana 
University, Bloomington, Indiana; Prof. Spencer Trotter, of Swartli- 
more College, Swarth more, Pennsylvania; Professor Miller, of Prince- 
ton; Prof. H. K. Mateer, of Wooster University, Wooster, Ohio; Mr. 
W. S. Marshall, of the University of Pennsylvania, and Mr. Geo. Howard 
Parker, instructor in biology, Museum of Comparative Zoology, Har- 
vard College, Cambridge, Massachusetts. 
Substantial assistance has also been rendered the Marine Biological 
Station established at Wood’s Holl by the efforts of citizens of Boston 
in giving the investigators and students connected with that institu- 
tion facilities in collecting, in company with the naturalists of the U. S. 
Fish Commission, on the expeditions made with the steam-launch and 
the U. S. Fish Commission steamer Fish Hawlc. In this way teachers 
and students who were not previously familiar with the methods used 
in deep-sea dredging were enabled to witness the most modern appli- 
ances in operation and obtain useful material not otherwise accessible. 
Similar courtesies were also extended by Commissioner McDonald to 
Professor Dwight, of Vassar College, and his pupils, who were engaged in 
scientific explorations and biological studies at Cottage City, Martha’s 
Vineyard. 
Summarizing, Johns Hopkins University was represented by five 
