Marcu 22, 1912] 
males as three hundred and eighty-one to three 
(381:3). (7) The bands on the abdomen, so 
conspicuous a feature of the normal fly, have been 
lost in another mutant. The factor is dominant 
and sex-linked.» (8) Another wing mutant has ap- 
peared in which the second inner vein fails to 
reach the margin, often producing a bifid wing, 
but the shape of the wing is varied. The wings 
are held out at right angles to the sides of the 
body. The factor responsible for this condition is 
also sex-linked. Thus bifid-winged females crossed 
with wild males give all normal-winged females 
and bifid-winged males. The reciprocal cross gives 
normal-winged males and females. These inbred 
give normal-winged females and males and bifid- 
winged males. 
Supernumerary Chromosomes and Conjugation of 
Chromosomes in Ceuthophilus (Sp.?): N. M. 
STEVENS, Bryn Mawr College. 
The usual number of chromosomes in the sper- 
matocytes of the first order is 19, eighteen bi- 
yalents and the univalent X chromosome. In one 
individual two supernumeraries, and in another 
one were found. These supernumerary chromo- 
somes behave like those in Diabrotica svror and 
D. 12-punctata, dividing sometimes in the first, 
sometimes in the second maturation mitosis; and 
they probably originate, as in the Diabroticas, in 
an abnormal division of the X chromosome. In 
Ceuthophilus synapsis or conjugation of the chro- 
mosomes takes the form of parasynapsis. The 
chromatin threads pair side by side, twist together 
and in the prophase untwist. The homologous 
members of each pair unite end to end, forming 
compound rods, crosses_or EH-shaped figures, or 
they may unite by both ends, forming rings. The 
first maturation mitosis is a segregation division, 
the second equational. There is no synizesis stage, 
and no marked polarization of the chromosomes to 
form a bouquet stage. 
This paper will be published in full in the 
Biological Bulletin. 
Chromosome Studies: F. PAYNE, Indiana Univer- 
sity. 
A continued study of the Reduviide throws no 
further light upon the origin of the irregular chro- 
mosome distribution found in that family. In 
Pnirontis, however, is found a type of distribution 
new to the family and similar to that of Gelasto- 
coris oculatus. In Pselliodes, which gives another 
type similar to that of Prionidus and Sinea, the 
single chromosome, the homologue of the small 
5 Proc. Soc. Exp. Biol. and Med., 1911. 
SCIENCE 
473 
idiochromosome, contains a larger quantity of 
chromatin than the three small chromosomes which 
go to the opposite pole. In this respect it is 
similar to the case of Acholla. A study of the 
ovaries of Gelastocoris reveals a nucleolus which 
forms shortly after the last oogonial division and 
remains until about the time of synapsis. In most 
cases this nucleolus stains uniformly, but in favor- 
able places darker bodies can be seen within it. 
It seems probable that these darker bodies are the 
idiochromosomes, eight in number. In these ovaries 
the ova can be traced with unbroken continuity 
from the end chamber to the fully developed eggs. 
To be published in full either in the Journal of 
Morphology or in the Biological Bulletin. 
The Histogenesis of the So-called Apyrene Sper- 
matozoa in Strombus: EpwiN E. REINEE, 
Princeton University. 
The apyrene spermatozoon of Strombus, as com- 
pared with the eupyrene or ordinary spermatozoon, 
of this species, is a very large cell with a com- 
plex structure. The cell-body is cylindrical and 
tapering in shape and it is filled with many polyg- 
onal bodies which are undoubtedly composed of 
albumen. These bodies are very regular in out- 
line and are arranged in rows; they vary consid- 
erably in size, those in the middle of the cell being 
larger than those at either end. The breadth of 
the cell is greatly increased by the presence of two 
undulating membranes which pass down either side 
of the cell and meet at the posterior end, where 
they are drawn out into a long sharply pointed 
tail-piece. Anteriorly these membranes fuse in the 
mid-line and give a broad, rounded appearance to 
this end of the cell. At the very tip, where the 
membranes meet, there is a darkly-staining cap; 
this is a centrosomal structure. Lying scattered 
through the cell and between some of the albu- 
minous bodies are fragments of greatly degener- 
ated nuclear material. The entire length of the 
spermatozoon is about 90 micra. 
spermatozoa are found to originate from certain 
large pear-shaped cells which are attached by their 
narrow ends to the eyst-wall of the testis. These 
cells are easily recognized and can readily be dis- 
tinguished from the eupyrene spermatocytes, not 
only by their size, but also by the presence of a 
large sphere with strong astral rays. The devel- 
opment of the apyrene spermatozoa from these 
cells is direct, that is, no cell-division occurs dur- 
ing their histogenesis; the nucleus simply breaks 
down, scattering nuclear fragments throughout the 
cell. These fragments immediately begin to degen- 
The apyrene 
