Vol. IX, No. 1.] Sponges of the Lake of Tiberias. 69 
[V.S.] 
upward course by the cortex cutting across them, is also greatly 
thickened, containing a large number of spicules lying more or 
less parallel. In both cases, however, the apparent thickening 
is due not to a thickening of individual fibres, but to a massing 
together of separate fibres. In the cortex the individual fibres 
can be seen crossing one another at right angles, and in a verti- 
cal section the spicules of some of them are always cut through 
the middle. The thickened ends of the vertical fibres are also 
composite and have extra transverse fibres linking them to- 
Of the internal soft part of the sponge there is, in the pre- 
sent state of our knowledge, very little that can be said with 
g abundan | 
although the sponge-cells are well preserved in some of m 
specimens, the vegetable cells are not and I can say little about 
their peste 
ave been unable to find any trace of gmmules. Sper 
dietiler Gulla are abundant in one specimen and another contains 
young embryos, which resemble those of Spongilla and Ephy- 
datia 
I only found C. barroist on small pebbles in the actual 
channel of the Jordan as it runs through the south end of the 
Lake of Tiberias between the village of Semakh and the exit of 
the river from the lake. The water in this channel is from 
4 to 8 metres deep. apeerees Barrois found his specimens in 
exactly the same spot; the differences between them and 
my own are to be attributed, directly or indirectly, to seasonal 
changes. 
Notre oN DeRMAL PORE-CELLS IN THE SPONGILLIDAE. 
Owing to its pei a and to the comparatively large size of 
its pores, NV. affords unusually good material for the 
study of the donsat gece Some of my specimens are very 
well preserved, having been fixed in picro-formol-acetic solu- 
tion, and I have been able to eigen aobangsot preparations 
of the dermal membrane and in some cases even of the whole 
sponge, that exhibit the structure “of that membrane with 
great clearness. ! 
method of preparation, originally sug; nines hed an accident, 
A nsv 
