32 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 134 
insects, such as Scarabaeidae (except Coprinae—see next paragraph) 
and lepidopteran larvae. As shown in the table, the present investi- 
gations have confirmed the predominance of the patterns previously 
reported for these groups. 
6. In the samples of Neotropical species of Passalidae and of 
Coprinae, the islands of coagulation characterizing pattern I were 
absent or exceptionally recorded in the samples, while in the African 
specimens studied until now (Grégoire and jolivet, unpublished), 
these islands of coagulation appeared frequently or consistently in 
many samples. In view of the scarcity of the material and the diversity 
in the reactions characterizing these two groups, random variations 
might be responsible for these divergences between the results. 
SUMMARY 
Coagulation of the hemolymph in vitro has been investigated by 
phase-contrast microscopy in 630 specimens from 230 Neotropical 
species of insects. The present material includes samples of hemo- 
lymph from insects belonging to 17 families not represented in previ- 
ous related studies. 
A tentative classification of the process of coagulation into four 
patterns, suggested previously, has been used, and the patterns charac- 
terizing provisionally each species have been determined and reported 
in tabular form. 
The Neotropical material and the data collected formerly on species 
from the Old World (altogether approximately 850 species), sup- 
plied consistent results with regard to the predominance of some of 
the patterns in several taxonomic groups of various extension in the 
classification. 
In a condensed form, the investigations on the distribution of the 
patterns of hemolymph coagulation in the different orders have shown: 
(1) In the Orthopteroid Complex, a great uniformity of reaction, in 
the shape of pattern I, possibly a generalized primitive mechanism of 
coagulation of the hemolymph; (2) in several families of Heteroptera, 
absence of a visible reaction in plasma (pattern IV), in striking con- 
trast to two families of the same order, Belostomatidae and Nepidae, 
which exhibited a substantial coagulation (pattern I) ; (3) in Homop- 
tera, a substantial reaction in the shape of pattern I, representative or 
predominant, in Cicadidae, Fulgoridae, and Cicadellidae; (4) in Co- 
leoptera, as a taxonomic group, a large heterogeneity in the reactions. 
However, in this order, uniformity of reaction or predominance of a 
pattern was detected at the infraorder level, especially in Hydrophili- 
