100 Wisconsin Academy of Sciences , Arts and Letters. 
by a broad pencil of refractive threads [s] which is to be regarded as the 
secretion of the pleuropodial cells. In Fig. 18 three of these curious cells 
are represented as they appear under a magnification of about 900 diam¬ 
eters. The inner ends which stain deeply in borax carmine contain a num¬ 
ber of very coarse granules among which are interspersed a multitude of 
finer ones; the granules diminish in number beyond the oval nuclei and 
have completely disappeared in the gradually tapering outer ends of the 
cells [Z], These ends are not affected by the stain. Each cell-tip is capped 
by a refractive thread, which nearly or quite equals the cell in length and 
may often be split into two or three branches. Usually the line which 
separates the cell-tips from the threads which cap them, is distinctly 
marked as in Fig. 17 and at z in Fig. 18. I have, however, found num¬ 
erous cases where no such line could be detected, the hyaline cell-tips pass¬ 
ing without interruption into the long refractive threads. The minute 
structure of the nuclei resembles that of the pleuropodial nuclei of Blatta. 
Through the faintly stainable caryochylema runs a chromatic reticultim, 
the nodes of which are irregular and much thickened. The nucleolus has 
little affinity for staining fluids and is probably to be relegated to Carnoy’s. 
class of “ nucleoles plasmatiques.” 
Sialis infumata, Newm. 
This Neuropteron oviposits on the leaves of plants overhanging the 
water. The eggs are arranged in regular rows, with their stem-shaped 
micropyles directed upwards. The embryos are so small that it is diffi¬ 
cult to obtain good surface views; still I have been able to satisfy myself 
that the first abdominaJ segment, at about the time of revolution, presents 
a pair of conical evaginated pleuropodia, which lie somewhat outside of 
the line of the thoracic legs. In my sections I could detect neither a dif¬ 
ferentiation of the cells nor diverticula of the body-cavity extending 
into these appendages. The apparent solidity of the organ may have been 
due to the thickness and the plane of my sections. 
PART SECOND. 
Gryllotalpa vulgaris. L. 
The pleuropodia of the mole-cricket were observed as early as 1844 by 
Batlrike [’44] who described them as mushroom-shaped bodies. Many 
years later, Korotneff [’85] in his account of the general embryology 
of Gryllotalpa figured and described the same organs more at length. 
According to this author they arise as button-shaped prominences, not in 
line with the other appendages but laterad to them. Their outline in sec¬ 
tion resembles that of a mushroom and they are seen to consist of succu- 
