222 Proceedings of the Royal Physical Society. 
alimentary canal appear as a brown mass extending from the head to 
the anus. When this streak attains a dark brown colour no further 
boiling is required, as a rule. In some cases, however, it may be necessary 
to sever the head from the body and boil it separately to soften and 
remove the mass of muscle it encloses. In such cases great care is 
necessary in dissection to prevent the head being torn and its appendages 
folded or distorted beyond recognition. 
INSTRUMENTS. 
For dissection a pair of very fine scalpels, or a pair of dissecting needles 
sharpened like a blade at the points, and a pair of fine-pointed forceps are 
all that is necessary. I have found it best to examine the larve first with 
a simple dissecting microscope having magnifications of 8, 12 and 20 
diameters. This last power is sufficient to distinguish the various parts of 
the head and the segments of the body, and in some cases the spiracles and 
spluules. For closer and detailed examination, and for sketching complete 
organs like the head or thorax, a Porro-Prism is very useful. Best of all, 
however, is a binocular dissecting microscope. The one I have used has 
a 10-diameter eyepiece, and objectives with working distances of 44 mm. 
and 32 mm. respectively. These have proved adequate for the most detailed 
examinations. In making sketches of the mouth-parts, slides were mounted 
and sketches made through an ordinary compound microscope and a 
camera lucida of the Abbé type. 
GENERAL DESCRIPTION OF THE LARVA. . 
The larvee of the Anobiid and Lyctid beetles are admirably adapted to 
the life they lead as wood-borers. They are soft fleshy grubs with a hard 
chitinous head sunk in the first segment of the body. The mandibles (or 
jaws) are well developed and powerful. The body is curved enabling the 
larva to progress in its tunnel by alternately extending and distending, 
thus pressing on the sides of the tunnel. This method of locomotion is 
further assisted in the Anobiid type of larva by the presence of spinules 
on the dorsal surface, and in the case of Ptilinus on the sides, of the body 
segments. The legs are six in number and very feeble. The antennz are 
much reduced and sunk in pits, except in the Lyctid larve. I have been 
unable to make out the presence of eyes of any kind, 
There are then two types of these larva, Anobiid and Lyctid. They 
are very much alike in appearance, and, to the casual observer, they appear 
quite similar. A general description of the two types may be useful before 
