No. 6 HEMOLYMPH COAGULATION IN INSECTS—GREGOIRE 5 
the shape of circular islands of granular consistency around the al- 
tered hyaline hemocytes. The islands of coagulation develop to a 
certain size, with individual and specific variations, then their increase 
stops. At the beginning of the process, the islands are scattered and 
separated by fluid channels. When the coagulation proceeds farther, 
the plasma in these channels clots into a granular substance in which 
the islands preserve generally their original size and shape. General 
solidification of the film may occur. The coagulum, of granular ap- 
pearance, is progressively modified into delicate meshworks of 
granular fibrils. 
Pattern II. Extrusion of cytoplasmic expansions by hyaline hemo- 
cytes, with development of cytoplasmic meshworks. Reaction in the 
plasma in the shape of veils (text fig. 2; pl. 1, fig. 6).—-On contacting 
the glass, a category of fragile hyaline hemocytes undergo alterations 
that differ from those observed in pattern I. These elements extrude 
threadlike cytoplasmic expansions, which may reach a great length. 
These expansions exhibit intense thigmotropism toward solid par- 
ticles, other hemocytes, and physical interfaces (bubbles). These al- 
terations result in constitution of cytoplasmic meshworks of various 
complexity, on which the other kinds of hemocytes are passively 
agglutinated. 
The reaction in the plasma after these cellular changes occurs in 
the shape of transparent, elastic, and contractile veils, developed 
within the cytoplasmic systems built up by the hyaline hemocytes, or 
in their vicinity. The other categories of hemocytes do not take part 
in the formation of these cytoplasmic meshworks. They are passively 
agglutinated along the highly adhesive cytoplasmic filaments sent out 
by the hyaline hemocytes and are subsequently embedded with them 
in the plasma veils. 
In several insects the alterations in the unstable hemocytes are not 
followed by changes in the plasma and the modifications of the hemo- 
lymph in vitro consist only of a cellular reaction. 
Pattern III. Patterns I and II combined (text fig. 3; pl. 1, fig. 
9).—The microscopical picture of pattern III consists of an asso- 
ciation of the reactions described above in patterns I and II. In the 
same film of hemolymph, hyaline hemocytes produce cytoplasmic 
expansions (pattern II) while islands of coagulation (pattern I) de- 
velop around the body of these corpuscles. The islands are either 
isolated or appear as denser areas within the veils characterizing the 
reaction in the plasma in pattern II. 
Pattern IV. No modification in the hyaline hemocytes, or altera- 
tions not followed by visible reaction in the plasma (text fig. 4).—In 
