ZOOLOGY .AND BOTANY, MICROSCOPY, ETC. 
62 L 
Diplopoda.* — Sig. F. Silvestri begins a monograph of Diplopoda 
dealing first with the taxonomy of the class. After giving a history of 
classifications he states his own, which is partly after Bollman, partly 
after Pocock, with various additions and modifications. His view of the 
general systematic position of Diplopoda is thus indicated : — - 
PROTRACHEATA 
A third chapter is devoted to a consideration of the copulatory 
organs, a fourth to a synonymy of parts, a fifth to a list of genera. Then 
follows the systematic description, ending with a bibliography of nearly 
fifty pages. 
Eye of Scutigera.j — Herr B. Kosenstadt points out that the eye of 
Scuiigera, which differs from the simple eyes of other Myriopods in look- 
ing as if it were facetted, and differs from facetted eyes in having two 
superposed rows of retinule cells, may be justly regarded as an inter- 
mediate stage between simple and compound forms. 
5. Arachnida. 
Variations in Limulus Polyphemus.* —Prof. W. Patten gives an 
account of some very remarkable variations in the king-crab. The 
principal value of his material lies, he says, in the large number of 
abnormal embryos, and in their range of variation from those that w r ere 
nearly normal to those that w r ere so modified as to leave a hardly 
recognisable being behind. The amount of material was so great that 
the author had in no case to use for illustration embryos, if there was 
the least doubt of their abnormality being real and not due to post- 
mortem abrasion, shrinkage, or other causes of like nature. 
The author has not entered into a critical discussion of prevalent 
theories of heredity and development in the light of these new facts, 
for it seems to him that everything of value in the way of argument has 
already been said, and re-said on the various phases of epigenesis versus 
evolution. When the smoke from the volleys of words discharged in 
the last few years has cleared away somewhat, Prof. Patten thinks that 
it will probably be found that the rival disputants are in closer agree- 
ment than they suspect. 
With regard to the appendages, it is pointed out that the three 
anterior pairs of thoracic and the abdominal appendages are most fre- 
quently absent. Indeed the absence of the latter is a very common 
phenomenon. When present they may exhibit want of symmetry. On 
* Ann. Mus. Civ. Genova, xvi. (1896) pp. 121-251 (26 figs.). 
t Zool. Anzeig., xix. (1896) pp. 369-75 (2 figs.). 
X Journ. Morphol.. xii. (1896) pp. 17-148 (10 pis.). 
