304 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
that they agree with the organs described by Joliet in the following 
points: — (1) They are both composed of two short ciliated tubes 
opening at one end into the body-cavity and at the other to the exterior. 
(2) They are both situated between the mouth and the anus in the 
vicinity of the nervous ganglion. (3) They are both destitute of a 
glandular portion, so that they cannot be looked upon as an excretory 
organ per se ; they can only serve as a passage for substances contained 
in the perigastric fluid. In this consideration it seems highly probable 
that in both forms the excretory function is carried on in the same manner, 
that is the leucocytes which absorb excretory products are thrown out by 
the action of the ciliated tubes. With regard to the relationship of the 
two main divisions of the Bryozoa, Mr. Oka points out that the 
Ectoproctous and Entoproctous forms agree in the following points : — 
They are all provided with a single nervous ganglion, and have a special 
organ for the exportation of leucocytes laden with excretory products. 
They are all small sedentary animals, generally united into colonies, 
with ciliated tentacles, and a U-shaped digestive canal. While thus 
maintaining the genetic affinity of Ectoprocta and Entoprocta, the author 
does not undervalue the points of agreement between the former and 
other forms of animals, such as Phoronis. 
Arthropoda. 
Myrmecophilous and Termitophilous Arthropods.* — Herr E. 
Wasmann has published a bibliography and catalogue. The list in- 
cludes 1177 species of myrmecophilous and 105 species of termitophilous 
insects. These are mostly Coleoptera (993 + 87). To these have to 
be added 64 Arachnids and 9 Crustaceans. The book also contains 
a critical sifting of the information which is available in regard to these 
associations. 
Herr E. Wasmann,! in calling attention to his book, lays emphasis 
on the numerous correlations between structure and habit. Certain 
tufts of yellow or reddish-yellow hairs on myrmecophilous Coleoptera 
are certain indications that their hosts lick these for the sake of an 
ethereal oil ; Aleocharinae, who are fed from the mouths of their hosts, 
have broad tongues and rudimentary labial palps ; the Clavigeridae, who 
also depend on their hosts, have rudimentary palps ; the Staphylinidae 
who accompany the almost blind Eciton-ants of Brazil resemble these, 
not in colour, which would be unprofitable, but in sculpturing, hairs, 
shape, and size. 
a. Insecta. 
Convergence and Pcecilogony in Insects. {—Prof. A. Giard calls 
attention to the difficulty of distinguishing between animals which in 
the adult stage are very like one another, while in the course of their 
development they appear to belong to quite different forms. It is 
necessary to distinguish insects of the same or of different genera which 
become like one another in the adult stage by convergence, and secondly 
* E. Wasmann, ‘Kritisches Verzeichnis der myrmekophilen und termitophilen 
Arthropoden,’ Berlin, 1894, 8vo. f Zool. Anzeig., xviii. pp. 111-4. 
X Ann. Soc. Entomol. France, lxiii. (1894) pp. 128-35. See Zool. Centralbl., ii. 
(1895) p. 81. 
