6 On a Cysticercus from Nyctereutes procyonides. 
readily traceable; it is not a perfect layer, but contains 
many interstices between the fibres, through which the sub- 
cuticular cells are continuous with those of the core. 
The subcuticular layer is composed of histological elements 
similar to those of the core, but is lessdense. It is penetrated 
here and there by vessels, contains calcareous corpuscles, is © 
continuous internally with the core through the muscular in- 
terstices, and is attached by fine fibres to the cwtzcle. 
This form presents the following points of interest :— 
1. The extreme variability in the length of the different 
specimens and the great absolute length (4 inches) of some of 
the longest specimens. 
2. The slight prominence of the head of the future Tenza, 
accompanied by the complete differentiation of the suckers. 
3. The probable absence of hooklets. 
4, The presence of a larval form of Tenia in a dog. 
Some of these facts might, I think, be accounted for if we 
assume that these larve have undergone their development in 
an unusual host. Prof. Huxley, in his paper on the Canidz 
(P. Z. 8. 1880, p. 262), speaks of Canis procyonides as living 
largely upon fruits and roots, and never attacking large 
animals, and as therefore not a purely carnivorous animal in 
the physiological, though it is in the morphological meaning 
of the term. 
But I have ascertained that the mdividual during the 
three years and eight months of his life in the gardens used 
to be fed on fowl’s heads and raw horseflesh. From the 
length of his residence in the Society’s gardens we may, I 
think, fairly assume that he took in the ova during his sojourn 
here, and that therefore these Cysticerci are probably the 
larvee of some common Tenia. ‘The presence of suckers and 
probable absence of hooklets would point to the adult being 
one with those characters. 
One naturally turns to Tenia saginata, Goeze, more com- 
monly known in this country as 7. mediocanellata, Kuchen- 
meister, as being the common hookless form also possessing 
pigmented suckers; and its identification with this form is 
strongly supported (1) by the small relative prominence of 
the origin of the head of the future Tania, (2) by the absence 
of hooklets, and (3) by the pigmented appearance of the 
suckers ; whilst against this the Cysticercus of T. saginata is 
only known to occur in ruminants, especially calves. And 
Monier believes on indirect evidence that the Cysticerci are 
never very numerous in the same host. He says (p. 58, loc. 
cit.) that “although this Tenia is much more frequent at 
Lille than 7. solium, we have not been able to come across 
