82 REPORT— 1887. 



produce spores, T starved it by depriving it almost entirely of ligtt, and 

 after a while by aerating the water only at intervals. As a result, after 

 some weeks, long (4 to 6 cm.), thin ('5 to '75 mm.), cylindrical pi-ocesses, 

 pointed at the end, grew out from the rhizome and leaves, pointing perpen- 

 dicularly upwards to a hole in the top of the box, through which a little 

 light came. These processes and the rhizome were very dark green in 

 colour, almost black, but usually white at the tips, while some were 

 dark green the whole length. When put into fresh sea-water those with 

 white tips burst at the tips, emitting a little cloud. On examining this, it 

 appeared to consist of protoplasm and chlorophyll bodies ; but the latter 

 were in very active oscillating motion, even when apparently quite freed 

 from the protoplasm. The motion differed from ordinary molecular 

 motion of particles in a fluid, in that there was very marked change of 

 relative position. It continued for some hours, when a damp chamber was 

 used. The bodies were of oval form, and in various stages of formation ; 

 groups of two, four, eight, and large balls of them, apparently consisting 

 of thirty or forty, were seen. I would have thought the balls due to the 

 contact of the protoplasm with the water, but I have since seen them in 

 the interior of processes preserved, stained, and cut with the microtome. 

 It appeared as if I had found the long-sought zoospores of Caulerpa, and 

 I cannot yet decide whether they were chlorophyll bodies or zoospores. In 

 specimens kept in a damp chamber I observed bodies of diflerent sizes, 

 the larger having more active motion than the smaller. I watched one 

 large one sailing about through the drop, and saw it come in contact with 

 a smaller one which was oscillating quietly. They coquetted with each 

 other for some minutes, and then appeared to become united in some 

 way, oscillated together for a while, and then stopped. I kept them under 

 observation for three days, but no further change took place, and the 

 rapid growth of bacteria in the drop appeared to kill them. Iodine killed 

 these bodies, stopped their motion, and rendered evident what I took to 

 be two cilia, but which may have been simjjly particles of protoplasm. I 

 have made many experiments, and have seen several apparent instances 

 of conjugation like the above, but have not been able to obtain further 

 development. The chlorophyll bodies of normal Caulerpa move so long 

 as any currents continue, but when these are prevented stop at once. The 

 processes, which were dark green throughout, and the rhizome did not 

 burst in a change of water, and when cut no protoplasm flowed out. Their 

 contents consisted of a dense mass of these chlorophyll bodies, or zoospores, 

 which showed the same movements when pressed out into water. Later 

 I found that a specimen of Caulerpa which had been kept in an ordinary 

 tank in ordinary light had produced a number of processes of a similar 

 kind, some of which burst spontaneously, with the same results as noted 

 above. Others became detached from the parent, developed rhizoids at 

 the previously attached end, flattened out to a leaf-like form, and are 

 growing well : these were branched considerably before becoming de- 

 tached. Some Carilerpa brought to me in the beginning of May from 

 the usual locality, the Magellina, showed profuse proliferation, the young 

 leaves arising from a narrow base and gradually expanding and branching 

 dichotomously, the branches also being flattened ; some of this material 

 which I have kept has continued branching, until at present a leaf about 

 9 cm. long has some 250 branches, up to the tenth order. The branches 

 produced in the aquarium are mostly long, thin, and cylindrical. The 

 material I have been receiving for some time past shows only the ordinary 



