178 MR. NEWPORT ON THE NATURAL HISTORY, ANATOMY, 
the inferior and posterior parts of the body of the pseudo-larva, thrust backwards in a 
packet, as it is slipped off at the period of change. In the absence of discovery of the larva 
itself, before it is full grown, this cast skin enables us to indicate its general form and 
economy, at that period of its existence, as surely as the fossil bone enables the compa- 
rative anatomist of the Vertebrata to indicate those of the habitant of a former world. 
The skin of the larva is fissured at the period of change along the median line of the pro- 
thoracic segment, and is extended forwards to the head and backwards to the meso- and 
meta-thoracic segments, exactly as in other insects. By carefully removing this skin from 
the pseudo-larva, and relaxing it in water for some hours, and then inflating it gently with 
a blowpipe, the general form of the larva is made apparent. It is a fat, yellow-coloured, 
elongated grub, with six short legs, formed of short coxal, femoral and tibial joints, covered 
with delicate scattered hairs, and with tarsi, each of which is a single joint, armed with a 
single short strong horny claw. The tarsal spines which exist in the very young Meloe on 
each side of this claw,—and which are of so much importance to the insect at that period 
of its existence in enabling it to cling firmly to its victim, and, relatively with other parts, 
are so large and conspicuous, that Léon Dufour derived from them the character of his - 
genus Triungulinus,—have entirely disappeared at previous changes of the tegument. In 
like manner also the caudal styles have been removed, being reduced to mere pointed 
tubercles, as in the larva of Cryptophagus*, preparatory to their complete obliteration in 
the pseudo-larva. The body is arched, slightly convex, and formed of fourteen segments, 
with a few scattered elongated hairs, as in the very young state; and also, as I have 
already mentioned, is covered on every part with multitudes of microscopic ones, scarcely 
one-thousandth of an inch in length, each proceeding directly from the centre of nearly 
every cell in this cast envelope. The segments of the body are nearly all of the same 
dimensions, and thus give to the larva a more uniform and less articulated appearance 
than that which it presents in its earliest state, when the segments of the thorax greatly 
preponderate. | 
The external organs of respiration have undergone but little change, éither in form or 
in situation ; excepting only that the second pair of spiracles are now of the same size as 
those of other segments. The small size of the whole, relatively to that of the body, seems 
to indicate a minimum degree of activity in the function of respiration, and consequently 
a sluggish mode of life, similar to that of the Bee-larva, in the abode of which the Meloé 
protected by a raised horny margin. Internally they are lined by a membrane made up 
of extremely minute but distinct cells, which form a layer that is continuous with the 
| | » which pass off from the main inus at acute 
angles, further prove that the capacity of the tracheæ, and consequently their function as 
respiratory organs, is insignificant and restricted. | 
This cast envelope of the full-grown larva shows that, up to this time, the head has 
* Linn. Trans. vol. xx. p- 352. tab. 14. fig. 34, 
