No. 399.] REVIEWS OF RECENT LITERATURE. 237 
temporary use of ether would call forth in the same plant a tempo- 
rary amitotic division, led Häcker * to subject developing eggs to the 
action of ether to ascertain whether their mitotic division could be 
converted into a temporary amitotic one. The results of these experi- 
ments are that when the eggs of Cyclops are subjected to the action 
of five per cent ether for from two to three hours, they begin to divide 
by a process many steps of which have all the appearances of amitotic 
division, and that after being returned to fresh water they reassume 
normal mitotic division. Cells, then, after dividing by what to all 
appearances is amitosis, may return to mitosis. Till further study 
proves absolute identity the author prefers to call this induced ami- 
tosis pseudoamitosis. P. 
A New Unattached Hydroid.— In a paper on Woods Holl Hy- 
droids, L. Murbach? redescribes Corynitis Agassizii and its medusa 
Gemmaria, and gives an account of a very remarkable unattached 
hydroid. It is represented by a single unbranched polyp of the 
Tubularian type with two circles of tentacles. A primitive perisarc 
envelops the hydrocaulus, at the end of which polyp buds are given 
off. Sexual reproduction takes place, the gonophores being between 
the two circles of tentacles. The polyp moves slowly from place to 
place and may be caught floating in quiet water. The author names 
it Hypolytus peregrinus and forestalls the systematic reviser by the 
statement: “Should the name here proposed for this new genus be 
preoccupied, I propose instead Gonohypolytus." P. 
Hydra Grafts. — The grafting of hydras has been studied by 
H. W. Rand? Lateral grafts do not persist as permanent abnor- 
malities, but either constrict and separate from the stock or are 
resorbed by it. If the graft is large or has tentacles, it, as a rule, 
eventually separates from the stock; if it is small and without dif- 
ferentiated parts it may be resorbed. All the pieces that were 
resorbed were much larger than the minimum piece capable of regen- 
erating if not employed as a graft. Lateral grafts differ from buds 
in that they do not separate from the stock as readily as buds do 
1 Hicker, V. Mitosen im Gefolge amitosen-ahnlicher Vorgänge, Anat. Anzeiger, 
Bd. xvii, pp. 9-20, 1900. | 
2 Murbach, L. Hydroids from Woods Holl, Mass., Quart. Journ. Micr. Sci. 
vol. xlii, pp. 341-360, Pl. 34, 1899. 
3 Rand, H. W, The Regulation of Graft Abnormalities in Hydra, Archiv fiir 
Entw.-mech., Bd. ix, pp. 161-214, Taf. V-VII, 1899. 
