H. A. Baylis 
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but differs markedly from them in having both a forwardly and a 
backwardly directed caecum; these are said to spring from the 
second or “glandular” division of the oesophagus. Pavoni, again 
(1906), has given an account, with figures, of a form which he calls 
“ Ascaris capsularia” His specimens measured only 10-20 mm. in 
length, and the younger individuals had two well-developed intestinal 
appendages, viz. a shorter dorsal and a much longer ventral caecum. 
In one example only 12 mm. long, there was no longer any sign of a 
boring-tooth, the lips were already distinct, and ovaries and uterine 
tubes were visible. Although this is mentioned as an instance of 
exceptional and precocious development in a larval form, it seems more 
probable that Pavoni was dealing with some much smaller species than 
A. capsularia, and that his specimens were already becoming adult. 
In any case all the three accounts cited seem clearly to refer to some 
form other than that which I have studied, and which I can only regard 
as the true “A. capsular ia” ; and doubtless a critical examination of 
some of the other forms recorded under this name would show that they 
were similarly misdetermined. 
Stewart (1906) has given what appears to be a reliable, though 
brief, account of the true A. capsularia, although admitting that the 
determination of his material is open to doubt. He has paid particular 
attention to the ventral excretory gland, which is a conspicuous and 
characteristic structure in this species. 
Stiles and Hassall (1899) include in their account of Ascaris decipiens 
some remarks upon certain immature forms also found in seals. They 
state that these forms agree essentially with the various descriptions 
of “A. capsularia ,” and with encysted specimens found in certain 
fishes, but do not attempt to define at all clearly what is, and what is 
not, the true A. capsularia, or to give a complete account of the anatomy 
of the larval forms seen by them. They express the opinion, however, 
that some of the encysted forms found in fishes probably represent the 
young stages of A. decipiens, and cite as probable intermediate hosts 
the Alaskan pollock ( Theragra chalcogramma) and the Pacific cod 
(Gadus macrocephalus), both fishes upon which fur seals are known to 
feed, and in both of which the larval nematodes were found. 
