90 
ALGOLOGICAL NOTES. 
escape, by a narrow opening near the upper end of the cell, as a 
gelatinous mass enclosing within it the rapidly moving bodies 
(Fig. 9 b). When once outside (Fig. 9c) their efforts seem 
redoubled with the object, apparently, of freeing each from the 
entanglement of the mucilage. The mass becomes looser, and one 
by one the individuals break away, spin round, return, and re- 
perform in the most lively manner the usual movements of these 
ciliate bodies. To observe at once a dozen contiguous cells, some 
filled with the moving masses, others with their contents recently 
discharged and just outside in even more violent motion, while a 
few of the exterior groups are loosening, — all this is a most enter- 
taining sight to the student. 
After swimming about for some time their movements become a 
little more sedate. A pair will waltz pretty rapidly together with 
their cilia touching (Fig. 10a) ; and shortly afterwards, the 
motions having gradually become slower, the hyaline beaks face 
each other, and, as the gametes become quiet, the union appears 
to have commenced (Fig. 10&). Later on the hourglass-form is 
reached (Fig. 10c), and ultimately a spherical zygosperm is the 
result (Fig. lOd). 
I am unable to say whether the gametes united with an indi- 
vidual from the same cell or not. I could detect no difference in 
the size (which is about 4 p in diam.) nor in the appearance of 
either gamete, and I was unable to wait for the germination of the 
zygosperm. 
These observations were made at Swanage in June, 1892. 
The median position of fertile cells has not been observed by me 
in any other species of Gladophora , and, indeed, generally the 
fertile cells are the uppermost ones and the condition extends 
downwards. 
Antheridia and spores of Prasiola stipitata Suhr. 
Mr. G. W. Traill was good enough to send me specimens of this 
alga collected at Joppa, near Edinburgh, in May, 1891. As they 
were placed at once by him in a saturated solution of sodium chloride 
they reached me in a condition practically the same as if just 
gathered. Many were in the reproductive state, and I found there 
were two kinds of organs, differing enormously in size, and on dif- 
ferent plants. I proceed to give the results of a study of them. 
Let us take first the large bodies which have been known some 
time. These are figured, though insufficiently, by the brothers 
Crouan ( Florule du Finistere , PI. ix., Gen. 68), and are the 
spores, the development and germination of which have been 
studied by Dr. Bornet (fFtudes Phyco logiques, p. 62). 
The surface view of the frond shows the green cells irregularly 
round and rather closely set, but generally in groups of four, each 
cell in the lower part of the lamina having a diam. of 5-7 p 
(Fig. 13a). Towards the upper part they are still in groups of 
