792 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Nervous System of Ascaris megalocephala.* — Herr R. Hesse con- 
tributes the following new points to our knowledge of the nervous 
system of this parasite. The sensory organs in the lips are of two 
kinds; there are papillae, the nerves of which pass through an orifice 
of the cuticle by merely becoming thinner, and there are others in which 
only a filamentar prolongation of the nerve traverses the cuticle, under 
the orifice of which there is stretched a membrane, the centre of which 
is perforated by the nerve. The distribution of the sensory organs is 
symmetrical ; the lateral nerves open at every pair of papillae ; the 
submedian nerves open at the labial sensory organs. The ventral nerve 
is doubly strengthened by the lateral ganglia ; a lateroventral nerve- 
bundle enters on either side, parallel to the nerve-ring, into the sub- 
cuticle, and a second into the connective-tissue bridge of the excretory 
vessel ; on its course as on its entry into the ventral cord there are 
numerous ganglionic cells. Of the commissures which pass from the 
ventral to the dorsal cord twice and a half as much goes by the right as 
by the left lateral ; the arrangement of these commissures differs but 
little in the two sexes. The sublateral nerves traverse the whole body 
of the animal, and at the hinder part of the body they pass into the 
lateral lines ; in the male the lower sublateral nerve in the tail end is 
strengthened on either side by the addition of nerves from the ventral 
line ; they thus become bursal nerves, but there is no nervus re- 
currens. In the female there are, near the tail end, a number of com- 
missures which extend from the ventral line to the lateral, but they 
are of small size. The vulva is only feebly innervated ; behind it there 
lie, at various distances dorsally from the lateral lines, papillae ; these 
are found also in the male. The dorsal and ventral cords divide at the 
caudal end ; the whole nerve-mass of each side is united into a lateral 
cord ; these lateral terminal nerves finally pass into one another. 
Embryos of Filaria Sanguinis Hominis.f — MM. de Nabias and 
Sabraze’s found in the hydrocele fluid of a patient who had just come 
from Guadeloupe, numerous mobile embryos of Filaria sanguinis 
hominis. They remained alive for two days, and their disappearance is 
supposed by the authors to be due to the development of bacteria in the 
fluid, for when 1 per cent, osmic acid was added the embryos lived for 
five days. The embryos possess neither alimentary canal nor generative 
organs, but consist of a number of nucleated cells ; in this collection of 
cells a clear space can be observed and this is supposed by the authors 
to be the site of the future alimentary canal or of the sexual organs. 
Classification and Distribution of Chsetognatha.J — Herr S. Strodt- 
mann, after a general resume of the structure of the Chaetognatha, 
enumerates the points which are of value in classification. These are 
(1) the size of the sexually mature animal, the proportion of length to 
breadth and of the three segments to one another; (2) the number, 
position, and size of the fins ; (3) the thickness of the epidermis and 
the size of the lateral enlargements of the same ; (4) the number, 
* Zeitschr. f. Wiss. Zool., xlv. (1892) pp. 54S-68 (2 pis.). 
t La Semaine Med., 1892, p. 212. See Centralbl. f. Bakteriol. u. Parasitenk., xii. 
(1892) p. 171. 
