65 
her, dass sie auf Schnitten kaum aufgefunden werden k6nnen.“ 
My own experience in respect to Procerodes and other marine Tri- 
clads is just the opposite to Lang’s, as I have had no difficulty to 
get the most brilliant preparations, using the sectional method after 
fixation with sublimate. The same is evidently the case for Bohmig 
and Wilhelmi, judging from the figures presented by them. 
In very young Leptoplanids living pelagically Lang (1. c.) ob- 
served cells „mit hbekeriger Oberflache", which, not without reason, 
he regards as adhesive cells. According to him, they oceur all 
over the ventral surface. 
As in Tricladida rnaricola, the adhesive cells of Emprostho- 
pharynx are arranged in a submarginal band and oceur in no other 
part of the body. In this broad area formed by them, there are, 
to repeat the faet, no ordinary supporting cells, the adhesive 
cells alone constituting it. Secretion oceurring b e tw e e n the cells 
is conveyed to the epithelium from subdermal giand cells, 
rhabdites as well as cyanophile secretion. The former might be 
distinguished from the ordinary rhabdites of epidermal origin only 
through their somewhat smaller size. 
The adhesive zone stands out perfeetly clear through the cha- 
racteristic content of the cells, the rods mentioned below, and 
through the faet that the surface is covered by very short, straight, 
hairlike projections. The cells are perhaps somewhat higher than 
the supporting cells of the adjacent area. The two former cireum- 
stances called my attention to them, as well as to the very conspieuons 
feature of a rich amount of subdermal giand cells in the marginal 
zone of the body. 
The nucleus is located in the basal half of the cell, inter- 
preted as adhesive organ. The exterior half of the cell presents the 
striking feature of parallely arranged, thick rods, strongly stainable 
with iron hematoxylin. These perpendicular rods reach the surface 
of the cell-body. Many of them might be followed to the base 
of the cell and have also been observed to continue in the strings 
of secretion passing from the parenchyma through the muscularis 
and basement membrane. While the conditions are very clear in 
the exterior part of the cells, it is, owing to the fixation, somewhat 
obscure in the basal part, not allowing one to definitively State how in 
detail the secretion is distributed to all the numerous channels in 
Vidensk. Medd. fra Dansk naturh. Foren. Bd. 79. 
5 
