Life-history of Phalacrocera replicata. 303 
founded, the cardiac body cannot be morphologically 
similar to the cellular rods of Phalacrocera. The other 
blood-glands described in Beddard’s “ Oligochveta ”’ are 
still more remote from anything that we have found in 
Phalacrocera. 
A second case of doubtful resemblance is found in the 
eleoblast of Tunicates. We have to thank Prof. W. A 
Herdman, F.R.S., for the following statement of the 
facts :— 
“The eleoblast of Salpa has been homologized by 
various writers with tne tail of a normal Ascidian. It 
projects from the ventral surface of the embryo near its 
posterior end, but is not exclusively epidermic. ‘There is 
a central mass of irregular vacuolated cells, more or less 
(according to the species and age of the embryo) in pro- 
cess of degeneration, which is supposed by Salensky, 
Brooks, and others, to be notochordal tissue. But the 
internal structure is rather indefinite ; it is very probably 
the degenerate representative of several tissues, and the 
eleeoblast seems to be formed at least partially by wan- 
dering kalymnoblasts (follicle-cells which have immi- 
grated into the embryo). A good deal of phagocytosis 
goes on in the eleoblast, and it becomes greatly reduced 
towards the end of embryonic life. A trace of it can 
sometimes be found ina young adult. It is difficult to 
trace any morphological connection between the elzoblast 
and the epidermic cords in the heart of Phalacrocera, 
though they may be physiologically comparable, since 
both exercise a nutritive function at a time of rapid 
tissue-formation.” 
Certain epithelia are known to be capable of resolution 
into substances which are sometimes, though not always, 
nutritive. In the secretion of milk, nuclei, filaments and 
oil-drops are liberated by the breaking up of epithelial 
cells.* Both cock and hen pigeons feed their young for 
some days after hatching, upon curdy masses formed 
out of the thickened and fat-laden epithelium of the 
crop.t 
‘The epidermis of various Fishes, Amphibia and Inverte- 
* Steinhaus, Die Morphologie der Milchabsonderung, Du Bois 
pena Archiv., 1892, Suppt. 
+ Waymouth Reid on 'Pigeon’s Milk. B.A. Report, 1894. 
