596 SUMMAEY OF CURRENT RESEARCHES RELATING TO 



some species of Stenostoma. To examine them in section cuts must be 

 taken in an oblique direction tbrougb S. leucops. The base of the pits is 

 covered by a pretty thick layer of uncoloured homogeneous substance, 

 which may be regarded as mucus ; below this is a thin layer of ciliated 

 epithelial cells, and there then follows a thicker layer, which consists 

 largely of pyriform cells, but also of other histological elements ; only one 

 nerve reaches close to the pits, where it divides and gives off a branch to 

 each little pit; this is shown to be sensory by its investment with very 

 small ganglion-cells. Teasing revealed the presence of bi-polar and some 

 multipolar ganglion cells, the processes of which form plexuses, ciliated 

 epithelial cells of various sizes, partly membranous cells which have an 

 investing function, goblet-like mucous cells, muscular fibres which cut the 

 plexuses at right angles, and special cells, which may perhaps be regarded 

 as sensory ; these last are rounded or oval, have a distinct nucleus and 

 nucleolus, and are on one side drawn out into a pencil-like process, and on 

 the other continued into a fine fibre. 



Distoma endemicum.* — Prof, I. Ijima has found that the form first 

 described in 1883 by Prof. Baelz as Distoma hepatis endemicum is found 

 not only in man but also in cats in Japan. The latter fact makes it easier 

 to trace the history of the fluke, but the author has not yet been able to 

 determine what inhabitant of the ditch-water it is into which the ciliated 

 embryos pass for an intermediate host. He doubts whether Baelz is right 

 in supposing that the parasites return to man in ditch-water, and suggests 

 that more worthy objects of suspicion are (1) Paludina and Corbicula, 

 though these are never eaten in a raw condition, (2) vegetables which have 

 been washed with ditch-water, or (3) a second intermediate host, such as 

 shrimps or various fishes. 



The parasite, when fresh, is translucent ; the body is about 11 ' 75 mm. 

 long, and its greatest breadth is from 2-2 • 75 mm., so that it is not unlike 

 D. lanceolatum in shape; the "brain" forms a bridge over the oesophagus, 

 and does not lie, as is usual, above or in front of the pharynx. What has 

 hitherto been taken for the ovary is a contracted mass of spermatozoa. 

 The ova are unusually small, and the embryos are of an elongated oval 

 shape, 0*025 mm. long; there are no eye-spots. 



Land Planariaiis.|— Dr. D. Bergendal has a preliminary notice of his 

 investigations on Bipalium kewense which has been found in the orchid- 

 houses of the Botanic Garden at Berlin. Eeferring to the question of 

 multiplication by transverse division, as to which it will be remembered 

 Prof. Bell made some observations to the Society last year,| the author 

 states that he has never been able to find sexually mature specimens, though 

 in one case sections showed small aggregations of cells which might be 

 regarded as rudiments of testes. Spontaneous transverse division was three 

 times observed in forms from which pretty large pieces had been cut off at 

 the anterior end ; the large quantity of small pieces which were found in 

 the hot-houses are, of themselves, sufficient to show that the phenomenon is 

 not very rare. 



The excretory vascular apparatus consists of a ciliated funnel with a 

 very strong " flame," irregular or plexiform canals, and longitudinal trunks. 

 The last undulate slightly, and two or more are found dorsally and laterally 

 to the enteric branches ; there are also ventral longitudinal trunks. All 

 consist of large cells, and have thick cilia, the papilliform basal portions of 

 which give a plexiform appearance to the walls. From these long trunks 



* Journ. College of Science Imp. Univ. Japan, i. (1886) pp. 47-59 (1 pi.). 

 . t Zool. Auzeig., x. (1887) pp. 218-21. J This Journal, 1886, p. 1007. 



