144 SIDNEY F. HARMER. 
into the cavity of the alimentary canal, but there were no 
other changes of importance. 
It may be here expressly pointed out that the history of 
this experiment, as traced from the 286th hour, refers specially 
to a single polypide, which was carefully examined and drawn 
at intervals of about twenty-four hours, so that the amount of 
time taken by the development was actually determined. 
Numerous other zocecia in the same colony completely con- 
firmed the observations made on this particular individual. 
My own observations unfortunately came to an end at 
the 520th hour, owing to my departure from Naples at that 
time. 
In the particular individual whose history has been traced 
to the 520th hour after the commencement of the experiment 
no special change had taken place in the leucocytes, which 
still contained the bright blue pigment. In some other indi- 
viduals of the colony, however, a much larger quantity of 
indigo-carmine had been taken up; so much so, indeed, that 
it did not at first appear possible that the zocecia could recover. 
After a time, as shown in fig. 9 (476th hour), the pigment was 
deposited in dense masses, no longer contained, as it seemed, 
in the leucocytes, but probably deposited by these cells in a 
more or less insoluble form. These masses were found in 
various positions in the zoccium, usually in the angles 
formed by the intersection of neighbouring sides, but some- 
times running across the body-cavity. It appeared pro- 
bable that in fig. 9 the “ lateral cords”? had formed a kind of 
focus, into which the pigment had been deposited from the 
neighbouring Jeucocytes. 
In the same individual (which was certainly alive, and in 
which the young polypide-bud may be seen in the figure) a 
mass of indigo-carmine had been deposited by leucocytes at 
the proximal end of the “‘ brown body,” while a similar process 
seemed to be taking place all round the ‘brown body,” 
though to a less marked extent than at the proximal end. It 
was further noticed that, in many individuals, the aggregation 
of the blue leucocytes round the “ brown body” was much 
