PROCEEDINGS OF SOCIETIES. - 321 
yet grown perfectly together or been differentiated to any higher 
degree. In such a state of development was yet one of the exhibited 
species called Enchytreus primevus. In fact, by looking at the 
different species, a perfect series could be seen of the different states 
of the development of said ganglion or brain. In Enchytreus 
nasutus the differentiation was larger, as the two halves of the brain 
here were wholly grown together, but still leaving some traces of 
their former state by being concave both in front and behind. In 
Enchytreus Stuxberguvi the differentiation was perfect, as the brain here 
was convex in front. Said worm was also considered to be more 
highly developed and organized than any of the other species of the 
same genus and family. Accordingly, he separated the many species 
into three tribes, of which the first or lowest had the brain concave 
in front and behind ; the second had the brain concave behind, but 
even in front; and again, the third or highest standing tribe had the 
brain convex both in front and behind. 
In the worms which were hermaphrodites were found organs of 
generation of two kinds—male and female. The female organs con- 
sisted of, first, ovaries containing eggs in different states of develop- 
ment, and second, of a pair of receptacles for the spermatozoa, 
peculiarly shaped, and varying in size and form in different species. 
The ovaries were generally found in the twelfth segment, the recep- 
tacles again always in the fourth segment of the worm counted from 
the head or the mouth. The male organs consisted of first, testes 
producing the spermatozoa, and second, of a pair of efferent ducts 
through which the spermatozoa were carried to the outside of the body 
and from there to the receptacles in the front part of the worm, where 
they were stored up in large quantities for future use. The testes 
were situated in or near the eleventh or twelfth segments, the efferent 
duct was always found in the eleventh segment. 
The minute anatomy and histology of said organs were shown 
partly by drawings, partly by microscopical slides previously pre- 
pared. The shape and development of the receptacles for the sper- 
matozoa furnished good characters by which the different species 
could be recognized. 
The system of circulation was very simple, and consisted only of 
a single ventral vessel uniting itself with a dorsal one in the front 
part of the body. The blood was either red or white, the last the 
most frequent. The lymphatic system was simpler yet, as here no 
vessels at all occurred, the lympha floating free in the perivisceral 
cavities of the body. The lymphatic fluid contained corpuscles re- 
sembling the blood-corpuscles of the higher animals, and in each 
species a different form of said corpuscles existed, giving good cha- 
racters for the distinction of the species. 
Dr. Hisen stated that he had also found several species of the 
same genus Enchytreus in California, and called the attention of the 
members of the Society to the value of even the smallest contribu- 
tions to a collection of California Hnchytrei, which he was forming 
and soon intended to work up. The said worms were frequently 
found in moist earth, in flower-pots, under decayed seaweeds, &c., 
