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XIX. The Natural History, Anatomy, and Development of Meloé (continued). 
By GEORGE Newport, Esq., F.R.S., F.L.S. Fe. ge. 
THIRD MEMOIR. 
The External Anatomy of the Larva of Meloë in its Relation to the Laws of Development. 
Read November 2nd, 1847. 
HAVING traced the natural history of Meloé, in the preceding Memoirs, I shall now 
examine its anatomy, with reference to those principles which regulate the formation of 
animal bodies, and which seem to be the links of connexion which associate peculiarities 
of instinct with the evolution, and with the functions of special structures, —commencing 
this with the ANATOMY OF THE TEGUMENT. 
1. The Tegument of the young Larva. 
The tegument, the parietal tissue of the body, little important as it may seem to be 
when cursorily examined in the adult Vertebrata, is nevertheless, in a physiological point 
of view, both in the vertebrated and in the invertebrated animal, the primary and essential 
foundation-structure of the organized being. Like the earlier tissues of plants, it is at first 
composed entirely of nucleated cells. It is derived immediately from a delicate, transparent 
layer of semifluid cells which constitute the blastodermic envelope that is formed around 
one portion of the yelk shortly after the disappearance of the embryo vesicle in the ovum, 
subsequent to impregnation. This has already been shown in the brief outline of the course 
of development, and in the delineations which I have given of the ovum of that “ atomie" 
of creation, Stylops* ; and I shall hereafter have to show that the same general laws which 
govern the development of that atomic existence regulate equally that of Heloë and of 
Man. This blastodermic layer of cells, folded on itself, and partially inclosing the yelk, is 
the structure from which the whole of the organized parts of the body concerned in the 
voluntary functions of the animal, are immediately derived; and, as embryologists are 
aware, it is to the foldings, the intus-susceptions, the extension or the shortening of 
portions of this structure that the primary form of the animal body is entirely due; 
whether it be that of the uniform and simply articulated worm, or of the rudimentary 
embryo of the most perfect of organized beings, Man. 
_ The principles which thus regulate the ultimate form of the embryo that is to be, and 
the origination of its future limbs, ere it has any definite structural existence, regulate 
also the whole of its growth and metamorphoses, whether these are gradual, uniform, and 
uninterruptedly continuous to their end, as in most of the Vertebrata, or whether they 
are marked by more rapid and extensive evolutions at some periods than at others, as in 
* Linnean Transactions, vol. xx. p. 337. t. 14. f. 23-32. 
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