128 
Walker . — On Abnormal Cell-fusion in the 
the visits. Through the kindness and hospitality of Mr, Wager, experi- 
ments were performed upon Polytrichum commune at Hawkswick, near 
Grassington, during the rainy Whitsuntide of 1912. The withdrawal and 
microscopic examination of the rain-water which had fallen upon ten 
antheridial rosettes resulted in the discovery of one free spermatozoid. It 
is probable, however, that the ripe spermatozoids of these rosettes had 
already been nearly exhausted during the preceding wet weather, as the 
extruded mucilage with imprisoned spermatozoids was not so abundant as 
when obtained in the laboratory from material kept for a few days under 
a bell-jar. Observations will be made when opportunity offers, to determine 
the effect of the local rain-water upon rosettes after fair weather, when many 
of the antheridia will be ready to discharge. Under favourable conditions 
an enormous number of spermatozoids is extruded from the antheridia of 
each rosette and a great wastage must result through the difficulty of their 
escape from the vesicles. It is possible that only the most vigorous 
specimens are thus selected for the operation of fertilization. 
The body of the escaped spermatozoid occupies somewhat less than 
a complete turn of a spiral and moves sluggishly corkscrew-wise through 
the water, ciliated end foremost. The vesicle of substance attached to the 
tail of the spermatozoid seems to effect a drag upon its movement and may 
afford nourishment during the long journey of the spermatozoid to an 
archegonial plant. The greater part of the distance is probably covered 
by means of the splashing of the rain, which would transfer spermatozoid- 
containing water from the very numerous antheridial rosettes to the drops 
of water which lodge upon the summits of the adjoining archegonial 
plants. 
I desire to thank Professor V. H. Blackman for many kindnesses and 
for his helpful advice given during the course of the investigation. My 
obligations are also due to Mr. G. H. Elam of Sedbergh, for his assistance 
in connexion with the collection of material. 
Summary. 
1. In Poly trichum formosum no fusion was observed to take place 
between the egg-cell and the large ventral canal cell. The fusion appear- 
ances described by J. and W. van Leeuwen-Reijnvaan are probably due to 
their special method of preparation of the material before fixation. 
2. In the spermatogenic cells the nucleus contains a large nucleolus- 
like body in which almost the whole of the chromatin is stored. This 
is connected with a peripheral reticulum by delicate radiating threads. 
3. During the prophase of division the chromatin is passed along the 
radiating threads to certain threads of the reticulum, which consequently 
thicken, and from these the spireme is organized. 
