REPRODUCTION IN LOWER PLANT LIFE. Lom 
of Staurastrum, from which our illustration is taken, it is 
very curious to watch the very rapid appearance of the 
spines on the half-bands while their development into 
half-cells is progressing. There is another very interesting 
phenomenon connected with the process which I do not 
remember to have seen recorded by any other observer. 
Desmids, as it is well known, have a power of apparently 
spontaneous motion through the water, somewhat re- 
sembling that of Diatoms, the cause of which is still 
involved in considerable obscurity. During the whole time 
that the division is taking place, the organism displays 
remarkable activity in this respect, not so much a motion 
of translation as a peculiar pulsating or “ shuddering”’ move- 
ment, reminding one of an animal subjected to external or 
internal irritation. When the new formation is completed, 
it becomes perfectly quiescent. 
We have seen that the higher Protococcoidez are pro- 
pagated by means of flagellate zoospores ; and this is the 
ordinary mode of non-sexual multiplication in all the 
bigher orders of Algee, except the Conjugate, the Fucacee, 
and the Floridez ; with the Phzeosporez and the higher 
Confervoidese they suddenly cease; and no organs of this 
nature are to be met with in the Characesze or any of the 
higher classes of Cryptogams. In all Cryptogams, except 
the Florides, the Conjugate, some Fungi, and the Myce- 
tozoa, the male agent in the process of impregnation is a 
flagellate antherozoid, bearing, in the lower orders, a close 
resemblance to a zoospore, but attaining a much more 
complicated structure in the more highly organised forms. 
Zoospores and antherozoids are alike generally charac- 
terised, as far as my knowledge goes, by the presence of 
the red ‘“‘eye-spot’’ or pigment-spot to which I have 
already alluded ; though I am doubtful whether attention 
