56 Mr. H. M. Bernard on the 
mass bound together by connective tissue. The walls of the 
duct are bulged out to form what look like short branches, 
but which are in reality only pocket-like outpushings. A 
large nucleus lies in each pocket. 
The cells of the duct are no longer demonstrable as simple 
cells; their outermost portions are arranged in strands of 
staining protoplasm and clearmatter. Lankester has suggested 
that these clear striae might be tubes; but I think it more 
probable that they are inflowing streams of the excretory 
matter. This excretory matter, after passing through the 
outer portions of the cells, seems to be absorbed by the nuclei, 
which swell enormously and bulge out the wall of the duct 
as above described. In this swollen state they no longer 
take stain, but are large clear vesicles which are detached 
into the lumen of the tube, where they finally break down. 
Besides these enormous nuclei (21 ~ in long diameter), others 
of all sizes are found, some comparatively small (12 y), with 
deeply-staining chromosomes. Although I have found no 
traces of dividing nuclei—dividing ¢@. e. in order to replace 
those which are cast off--Lankester has a figure * of the coxal 
gland of Buthus cyaneus in which the nuclei are obviously 
dividing. Between the nuclei and the lumen of the tube there 
is avery thin layer of staining and apparently undifferentiated 
protoplasm. 
While in Scorpio the nuclei appear, as above described, to 
absorb the excretory matter and to be cast off, in Galeodes 
this matter is apparently collected in vacuoles of the cyto- 
plasm, which are then detached and fiil the lumen of the duct 
with clear round vesicles. ‘The detachment of the nuclei in 
Scorpio has been mentioned by Lankester and Sturany ; 
but both seem doubtful whether this may not be due to the 
preparation of the sections. lig. 2, however, shows a portion 
of the duct in which there are more detached nuclei in the 
lumen of the duct than could have been derived from the 
wall, where, indeed, the nuclei are still found én s¢tu. Further, 
the different character of the nuclei (the solid staining and 
the large clear vesicular nuclei) seems to have escaped obser- 
vation. ‘The latter alone are found free in the lumen of the 
duct. ‘This remarkable function of the nuclei, as to the 
correctness of which I think there can be little doubt, deserves 
further investigation. 
This highly differentiated duct terminates, as is sometimes 
the case in Ga/leodes, in a sponge-like system of branched 
tubules. This mass of tubules does not, however, develop 
freely among the tissues of the body as in Galeodes, but is 
gathered together into a compact mass, round which the main 
* Quart. Journ, Mier. Sci. xxiv, pl. xii. fig. 5. 
