CARNOY’S OELL RESEARCHES. 483 
noy. This cord possesses a structure, which may be demon- 
strated in large specimens, and which must be attributed to 
smaller specimens by analogical reasoning. This structure is 
that denoted by the term “ boyau;” it is in fact a gut, con- 
sisting of a sheath and of contents. The sheath is structure- 
less, and is achromatic. The contents are the chromatin of 
Flemming, which Carnoy more frequently calls nuclein, being 
satisfied as to the rightness of this chemical denomination. 
The contents have frequently a figured arrangement. 
The gut may have a uniform calibre throughout; and this 
is taken to be the typical case. This is, according to my 
experience, the form most frequently met with in young 
nuclei. But very frequently, and especially in old cells, it is 
constricted at more or less equal intervals so as to become 
moniliform (fig. 2). The constrictions may become so deep 
that all the chromatin is forced out of the constricted parts 
and accumulated in the intervening bellies. Nuclei in this 
state are not infrequently described by authors as having no 
“reticulum,” but only a number of “ nucleoli” or “ granules,” 
the connecting bridges formed by the achromatic sheath 
between the globular chromatic swellings being easily over- 
looked. In senescent nuclei this process is very often carried 
much further, and the gut does actually become broken up 
into numerous elongated or globular segments. This process 
is perhaps often a pathological one, but in certain sorts of 
cells it appears to be perfectly normal. In ova it is the general 
rule, a rule to which there are very few exceptions. The gut 
splits into segments, and the segments run into drops or 
globules, the so-called “ germinal spots.’ 
Whilst the granular and globular forms of the chromatic ele- 
ment are derived from the filamentar form by processes of con- 
striction and segmentation such as these, chromatic networks, 
' Besides Carnoy’s figures, ‘ Biologie,’ pp. 222, et seq., and the statement of 
recent writers bearing on this point, | may be permitted to refer to my paper 
in the ‘Recueil Zoologique Suisse,’ I, No. 4, in which this process is described 
and figured for the ovum of Fritillaria. The actual specimens are much 
more demonstrative than my figures in this respect. 
