404 The American: Naturalist. [ April, 
nal vesicle communicates with the exterior. Present in Nephelis. In 
Clepsine it is equivalent to the terminal vesicle. 
The cells formerly called Chloragogencells, should now be called 
Exeretophores. A proliminary about these cells has been sent to the 
“Zoologischer Anzeiger.” The investigation had been carried out 
mainly on living tissues, and every source of error had been eliminated. 
—BASHFORD Dean, Secretary. 
SCIENTIFIC NEWS. 
John A. Ryder, Professor of Histology and Embryology in the 
School of Biology of the University of Pennsylvania, died on March 
26th. He was born in 1852 near Linden in Franklin Co., Pennsylva- 
nia, of old “ Pennsylvania German” stock, and displayed a strong 
predilection as a small boy for the study of nature. At school he was 
persistent in the pursuit of his favorite subject, and took little part in 
the sports and quarrels of the boys with whom he was associated. His 
sensitiveness to their criticisms was such that he ran away from school, 
only to devote himself more fully to study. He came to Philadelphia 
and was soon deep in microscopie work. At that time the methods of 
preparation of objects for the microscope were not as well understood 
as they have since become, and Ryder invented most of the methods 
which he used in his first researches. His studies of the embryology 
of fishes led to his appointment on the U.S. Fish Commission, where 
he published a number of important papers on the embryology of 
fishes and mollusca, and among the latter, the oyster was an especial 
object of investigation. In 1886 he was appointed to the position 
which he held at the time of his death. Professor Ryder was an 
indefatigable investigator, and his published papers, though numerous, 
give little idea of his activity. He has left behind him manuscript 
of considerable importance, which it is to be hoped will be published 
with the aid of a worthy editor. He was for a considerable time 
editor of the department of embryology of the American Naturalist. 
Besides excellent powers of observation, Professor Ryder had a 
mind naturally capable of comprehending mechanics. He patented 
several inventions of economic value. This tendency is to be seen 
especially in his application of mechanics to the problems of evolution, 
in which he presented many original ideas. He was a strong sup- 
porter of the Neolamarkian school ; and he carried this hypothesis into 
the explanation of histogenesis with more success than any American, 
