264 
Lernaeopoda 
oily-looking tissue cells, which make up the body of the host, from which the 
filamentous processes arise, and penetrate the cuticle projecting far beyond 
the surface of the animal. The central mass of the growth does not exhibit 
any structure, neither do the tapering filaments. The growths may have 
arisen from abrasions or wounds caused by the embrace of the male, the 
filaments possibly represent a vegetable growth that gained entrance to the 
wound. 
The Bulla. Since studying Clavella (Parasitology , xi, 120, fig. 4) it 
appears to me that what I have called the bulla in Lernaeopoda (Parasitology , 
viii, 268, fig. 4 a) corresponds only to the manubrium (“pedicel” of Wilson) 
of Clavella, and that possibly a cylindrical mass of tissue which fits into the 
saucer-like concavity of the upper portion of the strongly-chitinised organ 
in Lernaeopoda, which I have hitherto regarded as part of the host (wound¬ 
healing tissue), is the real bulla (homologous with the structure so called by 
me in Clavella ), derived from the frontal filament, while the manubrium is 
derived from the second maxillae. I fail to discover from Wilson’s text 
whether he bears out this view, and his figures of Lernaeopoda afford no 
explanation. His figures of enormous bullae in Salmincola (e.g. S. inermis 
with a bulla as large as the whole animal) seem to confirm my opinion. This 
mass of tissue is very slightly chitinised if at all, is vague in shape, possesses 
no markings, and is easily parted from the manubrial portion, so that it is 
almost invariably left behind in the host. 
Antennal Organs. Michael G. L. Perkins, whilst working with me, found 
that on staining the female with methylene blue and afterwards washing 
out with 90 per cent, alcohol all the stain was removed from the whole 
animal except from five spots in the antenna. These are indicated in 
Fig. 7, cf> 1 to 5. In perfectly fresh specimens they are visible under a lens, 
and the largest of them, <f> 1 , with the unaided eye, as pinkish spots. 
They occur also in L. galei and Z/. mustelicola, but so far I have not observed 
them in L. globosa which dwells in darkness. It is possible that they act as 
photo-receptors since they are supplied by the antennal nerve. As far as 
I know these organs (?) have not been recorded hitherto in any species. 
In specimens of L. galei and L. scyllicola stained by me with Romanowski 
for 24 hours, and afterwards washed in two changes of 90 per cent, alcohol 
for a week, it was found that the muscles and tissues were faintly stained 
with eosin, while nowhere did any traces of methylene-blue linger except 
in the five places mentioned. These places superficially appear to be chitinous, 
but it is noticeable that none of the rest of the chitin (represented by stippling 
in Fig. 7) is so stained, neither is methylene-blue a stain for chitin. 
The blue staining parts appear to represent organs below the chitin, these 
organs having a selective affinity for metbylene-blue. 
The Mandibles. On further examination I find that the mandibles, as 
previously figured by me in Part I, Fig. 3 c, are inaccurately drawn. I was 
for some time perplexed since it appeared to me that two types of mandibles 
