‘There is nothing more remarkable in this insect [the Water Scorpion] than that it constantly appears covered with a prodigious number of nits of different sorts and sizes, though perhaps we may with more reason consider them as so many little creatures, which live and grow by sucking the Scorpion’s blood. These are somewhat of an oblong figure, approaching to round, and have a shining, and as it were bloated, surface, without any of the rings observable in most insects. The neck is oblong and shaped like a pear, with the small end sticking in the Scorpion’s body. The colour of this insect is a mean between that of vermilion and purple; and when it is pretty well grown there appears within it an elegant transparent spot or particle (Fig. 59). [Illustration: FIG. 59.--Red Water Mite (nat. size, and under surface magnified).] ‘This spot or particle induced me to consider with more attention this minute and hitherto unregarded insect, and even to undertake the dissection of it. But who would imagine that on this examination it should prove a perfect and surprising insect? This is, however, a certain fact; and thus in that infinite variety of works, by means of which God is pleased to make Himself known to us, we ever meet with new matter of admiration and astonishment. ‘This little creature being extracted from the shell that covered it, looks like a young spider before it has left its egg. On the fore part is the head (Fig. 43D, _a_) and on its head are the eyes, _b_: under the eyes are placed its little legs elegantly coiled and folded, _c_ _c_; but they appear much more distinctly on turning the insect on its back, _d_ _d_; and in this situation also it best appears with what art these legs are laid up in the shell, and all are covered with hair. The colour of this little creature is, as I have already observed, a mean between that of vermilion and purple; and this colour shows itself through the coat or shell, which is transparent. I cannot determine to what species of insects this is to be referred; nor can I say to what size it grows, or by what kind of creature it is thus deposited on the Water Scorpion in the form of an egg, there to receive life and growth. Nevertheless, I cannot but look on the discovery I have made as very interesting, since it proves that there are in the nature of things eggs which acquire a sensible growth by an entraneous nourishment, unless perhaps some naturalist should choose to consider this as a complete insect, rather than as an egg; nor shall I strenuously oppose his opinion, seeing that, in all cases, the egg is in reality no other than the insect itself, which remains in that state till it has acquired sufficient strength to break its prison, and live without such a covering[35].’ Having quoted Swammerdam, let us see what De Geer has to say on the subject:--