446 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Blastocladia.* — Mr. R. Thaxter describes the structure of this 
remarkable genus of aquatic Saprolegniace®, which he places either 
among the Pythie®, or as the type of a separate family. B. Pringsheimii 
consists of a highly developed unicellular main axis, which is either 
simple or branched, and is attached to the substratum by numerous 
rhizoids. The ultimate form of the plant is very variable. It contains 
a number of spherical oily masses, the function of which was not 
detected, but which appear to have no connection with propagation. 
The only organs of multiplication observed were non-sexual, viz. 
zoosporanges formed at the extremity of branches, and large thick- 
walled resting-spores developed in similar situations. The zoospores 
are usually biciliated ; each contains a large nucleus, connected with 
the cilia by a fine strand of granular protoplasm. Their escape from 
the zoosporange is often prevented by the accumulation of immense 
quantities of bacteria. The outer wall of the resting-spore has a pitted 
appearance. 
Culture of Saprolegniaceae.t — Herr A. Maurizio gives the results of 
the culture of a number of species of Saprolegniaceae in different nutrient 
solutions, especially in reference to the production of conids. They can 
live and multiply only in water, a moist atmosphere being of no advantage 
if the substratum is dry. The author enumerates seventeen different 
species of fish that are attacked by different species of Saprolegnia and 
AcJilya, and considers that there can be no doubt as to the truly parasitic 
character of this group of Fungi. 
Parasites of the Nucleus and of the Protoplasm.^ — In the nucleus 
of Amoeba verrucosa , M. P. A. Dangeard finds a parasitic fungus which 
he describes as Nucleopliaga Amoebse, making it the type of a new genus 
of Chytridiace®. The parasite may consume the whole substance of the 
nucleus, and then frequently divides into a large number of roundish 
cells which impart to the nucleus the appearance of a sporange. It 
produces spores, probably zoospores, invested by a thin membrane and 
containing a nucleus. The genus appears to belong to the lowest 
Chytridiace®, near to Sphserita. 
Nucleophaga is very widely distributed among the Amoebse, and the 
author believes that its presence has given rise to many erroneous state- 
ments with regard to the mode of reproduction of the Rhizopoda, 
especially to the alleged propagation by zoospores and by “ovules.” 
He further believes that the study of the phenomenon of karyophagy 
may throw much light on the structure of the nucleus of the Rhizopoda. 
The life-history of Sphserita endogena , parasitic on the Euglene®, is 
then followed out in detail, the genus being very closely allied to 
Nucleophaga. Another parasite of Euglena, Olpidium Euglense sp. n., is 
described. It is found in the interior of the cytoplasm in the form of a 
spherical cell. In the process of propagation the parasite breaks through 
the cell-wall of the host, and forms outside of it a hernioid projection ; 
the zoospores are then formed within both the inner and the outer bladder,, 
escaping by the rupture of the thin wall of the latter. 
* Bot. Gazette, xxi. (189G) pp. 45-52 (1 pi.). 
t Flora, lxxxii. (1896) pp. 14-31 (1 pi.). Cf. this Journal, 1895, p. 79. 
J Le Botaniste (Dangeard), iv. (1896) pp. 199-248 (10 figs.). 
