1880 .J 
51 
batch is the result, the number of the eggs in which is equal to the 
sum of two successive ordinary batches of the same individual ; and 
^hen, as already mentioned, a beetle is interrupted in the middle of a 
batch, the next deposited eggs will be found to be the complement of 
the batch so interrupted ; and if there has been any considerable in- 
terval between these two portions, there will be a corresponding 
interval between their times of hatching out, showing that the eggs 
are only fertilized when they are about to be laid, or in their passage 
fiom the ovaries to the ovipositor. The interval between two layings 
varies in different individuals, and sometimes in the same individual ; 
but the average may be stated at two days or somewhat less. Twenty, 
thirty, or more than forty batches may be laid during the life of an 
individual. 
As to the arrangement of the eggs upon the leaf, the first thing 
to be noticed is that they are laid upon their sides, and not set 
on end like the eggs of butterflies and those of the Colorado beetle, &c. 
The typical arrangement seems to be in rows, to the axis of which the 
long axis of the egg is inclined, at an angle somewhat under 90°. 
These rows are commonly broken in the middle by an angle which 
may have been originally determined by the furcation of the nerves of 
the leaf. The ends of the eggs in each succeeding row fit into the 
intervals between the ends of the preceding one ; the last laid eggs, 
however, are commonly less regular in their arrangement. The whole 
batch has thus a somewhat fanlike or radiate appearance, and the apical 
or caudal angle, when it can be made out, indicates the first-laid end 
of the batch, and the direction in which all the tails of the future 
larvae will be found lying ; the first-laid end of the egg always (or 
nearly always*) being the caudal end. 
The individual egg is of a generally elliptical contour, about 1| — 
li millimetres in length by half a mm. broad ; but there is commonly 
a divergence from the perfectly elliptical form in two respects, im- 
pressed upon the egg, as it would seem, in the act of oviposition. 
During that pause of which mention has been made, after the first 
half of the egg has been extruded, its long axis no longer corresponds 
with the axis of the ovipositor, and a sort of curvature is impressed 
upon it, giving the egg a subreniform or sausage shape, except that its 
* I have recently met with two apparent exceptions to this rule, both in the same batch, and 
in a portion of it where the eggs were very regularly disposed. Two eggs, viz., one in the middle 
of a row and one at the end of it, lay with their heads in the same direction as the tails of all the 
rest. Now, if these eggs, lying orderly in line with the rest, were not laid head-first in place of 
tail-first, the beetle, in laying them, and those immediately after them, must have executed a 
very nice, difficult, and apparently useless manoeuvre in reversing her position some three or four 
times, so as to bring the eggs into the exact situations they would have occupied if she had gone 
on in the usual way. — J. A. O. 
