1897] NOTES AND COMMENTS 9 
draws his supply from the insect’s mouth, especially when she dis- 
gorges to feed a comrade. A mite carried on the abdomen of an 
ant taps, with his two front pairs of feet, another ant which happens 
to be near, and for thus asking obtains food. No benefit to the ants 
from the presence of these mites is suggested, and the relation bears 
the aspect of disinterested charity. 
Another species of mite, Discopoma comata, is on the other hand a 
true parasite. These gamasids attach themselves to the ant’s ab- 
domen, pierce the intersegmental membrane, and suck food-supplies. 
A bristle-tail or thysanure, Lepismina polypoda, plays the part of 
pickpocket in the ant-colony. He comes stealthily between two 
ants when one is feeding the other, grabs the drop of liquid nourish- 
ment in its passage, and makes his escape as quickly as possible to 
levy contribution on other couples until his hunger is satisfied. 
THE PIGMENTS OF THE DECAPOD CRUSTACEA 
ANOTHER interesting contribution has just been made to our know- 
ledge of the pigments of the decapod crustacea by Miss M. I. 
Newbigin (Journ. Physiol., vol. xxi, pp. 237-257, May 1897). 
She discusses the predominant characteristics of the pigments of 
Homarus vulgaris, Nephrops norwegicus and Astacus nobilis, The 
conclusions arrived at support recent observations on the same sub- 
ject, but a speculative tone mainly towards the end of the paper 
rather spoils the general effect. 
Thus we cannot accept the conclusion “‘ that there is some con- 
nection between the little known substance in the muscle and the 
formation alike of the blue pigment and of chitin.” The conclu- 
sion also that the red lipochrome is present as a calcium combina- 
tion in the shell is only speculation. The pigment is laid down 
there before calcification takes place: in fact pigment and calcium 
salt are more or less independent of each other. 
While in the earlier parts of the paper a distinction is drawn 
between the yellow and red pigments, in the ‘summary’ the former 
is said to be partially derived from the latter “ under the influence’ 
of certain reagents.” <A ‘lipochromogen’ is not a ‘compound’ of 
a lipochrome: it is a precursor of one. The return to Krukenberg’s 
term ‘ hepatochrome’ would certainly be unfortunate, as the organ 
in which such pigment or rather pigments occur is not a liver but 
mainly a pancreas, and although no band in red was recognised in 
extracts of the digestive gland by Miss Newbigin there is a chloro- 
phylloid pigment, which is better named enterochlorophyll, present 
in most if not in all cases. { 
There is no mention of this spectrum given by the pigment itself 
