46 PROGRESS OF MICROSCOPICAL SCIENCE. _ [ Mpnthls Mictoscopteal 
cellular glands described by Leydig, possessing fine ducts, that can in 
some instances be followed to the skin, and therefore almost preclud- 
ing the idea of their being hepatic organs. The nervous system pre- 
sents twenty-two ganglia, excluding the cesophageal collar; the last 
one is the largest, and is found in the anal sucker. No eyes have 
been discovered in them, and their relations to the outer world appear 
to be restricted to those derived from the sense of touch. The diges- 
tive organs present no remarkable deviations from that of the leeches 
in general. Its divisions are a proboscis, with its sheath; a crop; the 
gastro-ilial portion, and the rectum. The jaws are reduced to three 
minute projecting points. The crop extends quite to the posterior 
part of the body, and presents a series of constrictions. The gastro- 
ilial portion is a single tube lying above the cul de sac, formed poste- 
riorly by the ingluvies, and appears to correspond to the true stomach 
of other animals. The circulation is effected through a closed system 
of vessels, and the contents of these vessels are colourless, and desti- 
tute of corpuscles. M. Vaillant considers that the blood is represented 
properly by the fluid contained in the general cavity of the body, 
which contains definite morphological elements. There are four prin- 
cipal vessels, a dorsal, ventral, and two lateral, and these lie in the 
muscular layers. The dorsal and ventral vessels communicate freely 
by large branches; the lateral vessels receive their blood from a deli- 
cate plexus of vessels distributed on the intestine, which, however, 
communicates with the dorso-ventral system; and it is probable that 
an oscillation of the fluid is constantly occurring from one set of 
vessels into the other. On the whole, the vascular system is much 
less complicated here than in the leech. The respiratory function 
is effected essentially if not exclusively by the skin, and there is no 
special organ for its performance. In regard to the secretions, refer- 
ence has already been made to the unicellular glands of the skin; and 
the only others are some peri-cesophageal glands, which are generally 
considered to be salivary, and the muciparous follicles, which are 
ovoid vessels, six in number, on each side, placed in the testicular 
region, and opening externally with a ciliated orifice. The sexes are 
united in the same individual. The eggs are deposited either sepa- 
rately or several together enveloped in a common capsule. 
Is Eozoon of Animal origin ?—We have received a copy of the 
memoir presented by Messrs. King and Rowney to the Royal Irish 
Academy, and reprinted for private circulation by the authors. It is 
a bulky brochure, and is illustrated by four chromo-lithographs which 
don’t say much for Irish lithography. The whole tone of the paper, 
from beginning to end, is so distinctly personal that to the impartial 
student of science it is not pleasant reading. So far as we have 
studied it, however, it seems to us that the authors’ case is as hopeless 
as ever. Nothing that we can find is sufficiently strong in our opinion 
to overthrow Dr. Carpenter’s opinion that Eozoon is of animal origin. 
It is almost impossible for anyone who has scen the exquisite speci- 
mens which Dr. Carpenter long ago exhibited to the Royal Society to 
avoid the conviction that Eozoon is a fossil protozoan ; and we believe 
that, with the exception of Messrs. King and Rowney, all histologists 
