518 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
tions with the steam launch and tow net to the vicinity of Gay Head 
and Penikese to collect living examples of Salpa , besides one trip on 
tbe U. S. Fish Commission schooner Grampus as far out as the Gulf 
Stream for the same purpose. The last of these expeditions was partially 
successful. The object of collecting this material is to get a basis for 
comparison with the life history of tbe simpler forms of Tuuicates and 
to work out the precise method of the budding and development of the 
young Salpa , a problem to which Dr. Brooks has devoted much atten- 
tion, as may be learned from the very important memoirs which he has 
published on the subject. Mr. Morgan has made sections of the repro- 
ductive organs and sexual products in relation to the parent of the 
other five genera for comparison with Salpa , and will doubtless reach 
important conclusions upon completing his studies. 
Prof. W. K. Brooks, of Johns Hopkins University, Baltimore, has 
continued his extensive and elaborate studies upon the medusse and 
hydro-medusae of the Atlantic coast at the U. S. Fish Commission Sta- 
tion at Wood’s Holl. Prof. Brooks’s studies have hitherto been confined 
in the main to those upon the southern coast of the United States from 
Maryland to Florida and the West Indies, especially the Bahamas. 
During the 10 years of his work as director of the Chesapeake Zoolog- 
ical Laboratory of Johns Hopkins University he has accumulated sev- 
eral thousand sketches and beautifully finished studies from life of this 
group from materials obtained over the very wide marine area men- 
tioned above. These results have enabled him to compare the northern 
and southern forms, for the first time at Wood’s Holl, on the basis of a 
wider acquaintance with the different types ranging over this area 
than is probably possessed by any other student of these groups. Sev- 
eral common forms found about Wood’s Holl, usually regarded as the 
same as ttie southern ones, have been found to represent allied but dif- 
ferent species, with either a different liatoit of growth or a somewhat 
different life- cycle. 
Professor Brooks has made studies of the life histories of the following 
genera of medusae and hydro-medusae: Gyanea , Dactylometra , Mnem- 
iopsis , Pmnaria y Pelagia , Hydractinia , Tul)ularia y Pliysalia , Gampanu- 
laria , Margelis , Lafcea , Dipurina , Regmatodes , Clava , and JEudendrium , 
all collected near the station. Not only have careful drawings of the 
adults of most of these been made, but studies of their life-cycles or 
metamorphoses and development have been carried out. Suites of very 
. carefully preserved materials have also been collected for further 
investigation of the embryology, histology, and minute anatomy of these 
animals. The drawings by Dr. Brooks, illustrating the life-cycle and 
metamorphosis of the individual species, are not surpassed for accuracy 
and attention to details by any recent work, and can only be brought 
into comparison as respects the thoroughness and beauty of illustration 
with the classical monographs of Agassiz, Allman, and Haeckel. 
Dr. Brooks accompanied the expedition of the U. S. Fish Commission 
