968 The American Naturalist. [November, 
production either among hydroids or any other of the metazoa, 
and I propose for it the name Stoloniferous reproduction on ac- 
count of the great similarity which it bears to that process 
among plants.’ 
Asexual multiplication has long been known to exist among 
the hydroids, where it usually presents itself in some form of 
gemmation. Fission has been found to occur in a medusa, 
Stomobrachium mirabile Köll., but the most remarkable case 
heretofore recorded is described by Allman in a campanula- 
rian named by him Schizocladium ramosum? The process is, 
in brief, as follows: 
An ordinary ramulus, instead of bearing a hydranth on its 
distal end, elongates and the ccenosare ruptures the chitinous 
investment at the tip and protrudes naked into the water. 
constriction takes place by which this naked ccenosarc is 
divided off and finally separated from the parent stem. “The 
detached segment is now the rivof an inch in length, and 
strikingly resembles a planula in all points except in the total 
absence of vibratile cilia. It attaches itself by a mucous ex- 
cretion from its surface to the walls of the vessel, and exhibits 
slight and very sluggish changes of form. After a time a 
bud springs from its side, and it is from this bud alone that 
the first hydranth of the new colony is developed.” 
Although this process resembles the stoloniferous multipli- 
cation of Plumularia pinnata in the formation of a new colony 
from a modified branch termination, it differs greatly in the 
fact that in Schizocladium the divided portion or “ frustule,” as 
Allman calls it, becomes entirely separated from the parent 
stock before the new colony begins to develop, while in P. pin- 
nato, there is a vital connection by means of the greatly elonga- 
ted hydrocladium. 
The stoloniferous multiplication must not be confounded 
with any of the many modes of branching heretofore found 
among the hydroids, which do not give rise to separate colo- 
1“ Stolons are trailing or reclining branches above ground which strike root 
where they touch the soil, and then send up a vigorous shoot which has roots of 
its own, and becomes an independent plant when the connecting part dies, as it 
does after awhile.” Gray, School and Handbook of Botany, p. 37. 
? Report Brit. Association, 1870, and “ Gymnoblastie Hydroids,” p. 151, 152. 
