NOTES AND MEMORANDA. 
297 
to print here a translation of the article m extenso with the plates, 
but meantime the following summary of M. Balbiani’s observations 
will show the general conclusions at which he arrived. 
In the existence of N. WernecMi there are two periods, the one of 
freedom, the other of parasitism in the tubes of Vauclieria. In each 
of these two phases of its existence it assumes a very different form. 
In the first it is elongated, vermiform, and divided exteriorly into 
very distinct segments. In the second, when it attains the age of 
maturity, it is dilated, very contractile, and without any trace of seg- 
mentation. 
To these exterior changes correspond important modifications in 
the internal organs, characterized particularly by the enormous de- 
velopment of the ovary and the atrophy of the salivary and gastric 
glands. 
As with many other Kotatoria, it lays two kinds of eggs, called 
summer eggs and winter eggs, which are distinguished from one 
another by their structure no less than their mode of development. 
The same female may produce either summer or winter eggs 
exclusively, or the two kinds mixed in the same gall. 
The winter eggs are produced as early as the spring ; their laying 
commences later and is prolonged longer than that of the summer 
eggs — the latter are developed immediately, whilst the former 
hybernate, and are only hatched in the following year. 
Males were not observed, and on the other hand spermatozooids 
were never found in the females ; whence it is concluded that the 
winter eggs, like the summer eggs, develope without previous fecun- 
dation. 
The galls of Vauclieria, in which the animal lives and is repro- 
duced, are due to a hypertrophy of the branches of the plant which 
bear the organs of fructification. They differ from the galls, properly 
so-called, of the higher plants, in that they are pre-existing parts, 
which have simply undergone an increase of volume under the action 
of the parasite. This exaggeration of the vegetative functions is also 
often manifested by the formation of adventitious branches on different 
points of the surface of the gall. 
The exit of the young born in the galls, and their re-entry into the 
tubes of the Vauclieria to form new galls, is effected by openings 
which are produced spontaneously at the summit of the adventitious 
branches. They also sometimes make use, for the same object, of 
the male organ of reproduction, which persists at the base of the 
capsule in the form of a tube open at its two extremities. 
“ Bismarch Brown ” as a Staining Material. — In the ‘ Archiv fiir 
Mik. Anat.,’ vol. xv. part 2, is an article by Dr. C. Weigert on the 
superiority of this pigment over those hitherto used. The require- 
ments in a good staining matter are, he says : — (1) It must stain with 
perfect certainty, so that nothing is left to accidental circumstances 
or the ability of the histologist. This condition is not fulfilled by car- 
mine, picrocarmine, or eosin. (2) The stain must take quickly. In 
this respect, too, the two first-named pigments are defective. (3) Over- 
staining must not take place too readily, or must be capable of cor- 
VOL. I. Y 
