No. 2.] COMPARATIVE CYTOLOGICAL STUDIES. 313 
langere fadige Aufreihungen, deren Strange zu Schlingen gebo- 
gen oder geknickt sind.” In these ova two kinds of nucleoli 
may occur, namely, numbers of the small ones just described, 
and 3, large one with dark contours, which has a central 
vacuolar, granular portion, and is peripherally homoge¬ 
neous ; but nucleoli also occur which are intermediate between 
these two kinds. Geophilus electricus: here are numerous 
small, pale nucleoli and a large one, which has a finely granu -1 
lated core, and an outer homogeneous layer, the latter portion 
consisting of concentric layers; further, he noticed the infundib¬ 
ular structure first found by Balbiani on the outer surface of 
the nucleus, though he remarks that it is especially apparent in 
eggs in which post-mortem changes have commenced (!), and 
concludes : “ Wir haben es sonach beziiglich des Trichters mit 
einer Ausbuchtung jenes Hohlraumes oder Lichtung zu thun, 
welche von der Hohlung um das Keimblaschen herum in den 
Dotter dringt.” The basis of this infundibulum empties into 
a space around the nucleus, and not into the nucleus itself (as 
opposed to Balbiani’s observations); Leydig also thinks that 
particles of finely divided nucleoli penetrate separately out of 
pores which are present in the nuclear membrane, and that 
these particles, arrived in the cytoplasm, fuse together to form 
a large “Ballen.” Stenobothrus: in the ova of the proximal 
portion of the egg tube there are either numerous small nucleoli 
or a dense mass of very fine granules ; in riper germinal vesicles 
they are much larger and resemble somewhat the nucleoli 
in the salivary glands of Chironomus; masses of nucleolar 
substance wander out of the nucleus into the cytoplasm. In 
Pemphigus bursarius there is one compound nucleolus, with fine 
radiating processes ; and in Meloe violaceus there are numer¬ 
ous nucleoli, each of which has the structure of the single one 
of the preceding species. Gasterosteus aculeatus: in the month 
of May there are numerous germinal spots, sometimes densely 
grouped, sometimes arranged in rows ; the gradual thickening 
of the nuclear membrane takes place at the cost of nucleolar 
substance. Triton taeniatus: the germinal vesicle at the end 
of October contains numerous nucleoli of unequal size, many of 
which are arranged in columns ; the peripheral ones probably 
