368 LEFEVRE. [Vov. XIV. 
While the Marine Laboratory of the Johns Hopkins Uni- 
versity was stationed at Beaufort, N.C., during the summer of 
1894, I collected material for the purpose of studying the devel- 
opment of the buds of Perophora viridis Verrill, which was 
found there in great abundance. This material I supplemented 
the following summer at Woods Holl, Mass., while working in 
the laboratory of the United States Fish Commission. 
My main object in undertaking the investigation was to 
compare the bud development of Perophora with that of 
Botryllus, as described by Hjort (8) and others, and especially 
to determine, if possible, the origin of the nervous system. 
The material, which was easily obtained at both places in 
large quantities, proved to be most excellent for my purpose, 
as it contained an unlimited supply of buds in all stages of 
development. 
The preserving fluids used were (1) glacial acetic acid, (2) a 
mixture of eighty parts concentrated corrosive sublimate solu- 
tion and twenty parts glacial acetic acid, and (3) Perenyi’s fluid. 
The latter reagent gave perhaps the most satisfactory results, 
although very good preparations were obtained with the subli- 
mate-acetic mixture, when the objects were left in it not longer 
than ten minutes. 
Mayer’s haemalum proved to be most serviceable, while 
borax carmine gave an excellent stain when used after acetic 
acid or sublimate-acetic, but was of no value for objects fixed 
in Perenyi’s fluid. 
I have made use of Patten’s method of orientation (21) with 
great advantage, and have found it of invaluable assistance in 
manipulating very small buds, which I have been enabled to 
cut with accuracy in any plane desired. 
In studying the bud development of Perophora I have 
employed serial sections of all stages in the sagittal, frontal, 
and transverse planes, and also a complete series, throughout 
the entire development, of buds mounted in various positions 
as total preparations. 
The sections were cut from 3 to 5 mw in thickness on a 
Thome microtome, and all the drawings were made with the 
aid of a Zeiss camera lucida. 
