76 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
the stem of Botryopliora Conquerantii , and spherocrystals of inulin in 
sterile specimens of the same species. 
Phytophysa.* — Under the name Phytophysa Treubii , Mdme. Weber 
van Bosse describes an epiphyllous alga from Java belonging to 
the Phyllosiphonaceas, found on the stems, leaves, leaf-stalks, and 
buds of a species of Pilea , where it causes internal galls. Phytophysa 
resembles Phyllosiphon in its manner of living, in part, at least, at the 
expense of its host. Both are surrounded by a thick membrane ; Phyllo- 
siphon is rich in grains of starch, Phytophysa in grains of cellulose ; in 
both each cell contains a considerable number of minute nuclei. Phyto- 
physa is distinguished from Phyllosiphon by its spherical form, and by 
producing galls. 
Gonium pectorale.j — Dr. W. Migula has subjected this organism to 
a careful investigation, and finds that the entire colony, as well as each 
individual cell, is inclosed in a mucilaginous envelope, often of extreme 
tenuity, and of nearly the same refrangibility as water. The interstitial 
space between the envelopes of the separate cells is composed of a central 
quadrangle and four longer and twelve shorter isosceles triangles. 
When the colony consists of only four cells, there are two more or less 
regular usually isosceles triangles, thus presenting a clear distinction 
from G. tetras , in which the four cells are arranged around a nearly 
square intercellular space. The young colonies are already surrounded 
by their envelope when they escape from their mother-colony. The 
protoplasm of the cilia presents somewhat different reactions from 
that of the cells, and their vibratility is confined to their apical 
portion. When cell-division is taking place, the cilia of the mother- 
cell persist often until the sixteen daughter-cells are fully formed. 
The movement of the colony is of a more trembling nature than that of 
Volvox ; and there are no protoplasmic threads connecting the cells. 
The Gonium-colony enters into a resting condition as a result of desicca- 
tion, closely resembling that of Pandorina ; the membranes become 
thicker and denser, and the cilia disappear, as do finally the pigment-spot 
and the two cilia. The resting-cells have a diameter of about 12-15 p ; 
they are dark green, and are filled with a granular endochrome. Each 
breaks up on germination into four biciliated swarm-cells, closely resem- 
bling the cells of an ordinary Gonium- colony, but at first wanting the 
mucilaginous envelope, which, however, is soon formed ; these developed, 
as far as was seen, only into four-celled colonies. In the resting con- 
dition the Gonium- cells are very liable to be attacked and entirely de- 
stroyed by a parasite. The chromatophores break up very readily into 
a number of very minute chlorophyll-granules. 
Fossil Algae. J — M. G. Maillard classifies all structures described as 
fossil algaB under two categories, viz. : — (1) Those which appear as 
simple half-cylindrical elevations on the under-side of the strata, and are 
always more or less compressed. (2) Those which can be separated 
from the rock in which they are imbedded. To the first category, the 
* Ann. Jard. Bot. Buitenzorg, viii. (1890) pp. 165-88 (3 pis.). 
t Bot. Centralbl., xliv. (1890) pp. 72-6, 103-7, 143-6 (1 pi.). 
j Mem. Soc. Pakeontol. Suisse, xiv. (1887) 5 pis. See Bot. Centralbl., xliii. 
(1890) p. 126. 
