( cliii ) 
one of our commonest British species, Zenthredo mesomela 
of Linné. He also quotes at great length from a translation 
of Réaumur’s “ Mémoires,” and proceeds to notice phenomena 
which he believed that author—and indeed all others—to have 
overlooked. 
The true saw, he tells us, is not the object commonly so 
called ; but another, as yet undetected, and figured by him 
now for the first time. What has been called the saw is only 
a sheath, in which the real saw is enclosed during quiescence. 
He describes minutely such characters of this object as are 
visible in the lateral view of it, and explains how, precisely, 
it is adapted to the functions which he assigns to it. 
Now—will you believe me?—-this previously undiscovered 
“true saw” is simply one of the “supports.” It had been 
figured and described quite adequately both by Réaumur and 
Vallisnieri. And the edge of it which the later author sup- 
poses to be its cutting edge, is that which is at all times in 
contact with the upper margin of the veritable cutting- 
instrument, and is consequently owt of contact with the 
materials which it is said to act upon! 
2.—The mistakes of the other author are not of his own 
making. But he lends his great authority to support a 
strange notion imparted to him by an entomological friend. 
He tells us that this friend had watched repeatedly the opera- 
tions of Sawflies, and had found out that Réaumur and others 
were mistaken in supposing that the eggs travel through the 
instrument which makes the incision. The latter instrument, 
he says, after making its incision is immediately re-enclosed 
within the sheath, and so remains while another quite distinct 
organ—the real ovipositor—is protruded from the abdomen, 
conveying with it an egg, which it guides into its proper 
position. 
As to this I can only say that I have never seen a scalpellum 
re-enter its sheath between the two operations of excavation 
and oviposition ; that I have watched again and again an egg 
enter and pass through the same organ which had prepared 
just before, a receptacle for it; and that, after dissecting 
literally hundreds of Sawflies belonging to various genera 
and species, I have never found anything in the least resem- 
