360 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
The Apodidae.*— Mr. H. M. Bernard, struck by the resemblance 
between the organization of Apus and that of a carnivorous Annelid, has 
investigated the Apodidae in order to discover whether this resemblance 
was due to homology or analogy. He works out in detail the possibility 
of the derivation of the Crustacea from Annelids, and he “ uses Apus as a 
key to solve the hitherto unsolved problems as to the origin of the Crus- 
tacea, and the true affinities between the various groups.” In the second 
part of his work appeal is made to the palaeozoic Crustacea, and the con- 
clusion is reached that, if Apus is to be derived from a carnivorous 
Annelid, a similar derivation must be allowed for the Gigantostraca. 
The author exhibits his views as to the relationship of Apus to the 
rest of the Crustacea in the accompanying scheme. 
Vermes. 
a. Annelida- 
Compound Eyes of Annelids.f — Mr. E. A. Andrews, who has 
already j published a preliminary notice of his investigations, now deals 
in detail with the eyes of Potamilla and Sabella. Those of the former 
are numerous cones of modified epithelium of the main stems of the 
cephalic branchiae ; each is composed of elongated, pigmented cells, a 
few of which have peculiar refracting bodies in their outer ends and 
modified axial parts. These, which may be presumed to be the sensory 
cells, have pigment only in the superficial part of their protoplasm. 
As each sensory element is separated from its neighbours by inter- 
vening pigment-cells such an eye is compound. In a species of Sabella 
and of Dasychone the eyes have essentially the same structure ; in one of 
Hypsiocomus the branchial eyes are not compound, but are comparable 
to one of the elements of the just described eye. 
* ‘ The Apodidae, ’ London, 8vo, 1892, 316 pp. and 71 figs. 
t Journal of Morphology, v. (1891) pp. 271-99 (2 pis.). 
J See this Journal, 1891, p. 738. 
