Page:Proceedings of the Royal Society of London Vol 60.djvu/208

188 The first is drawn from results of experiments performed on ferric chloride containing 0'086 gram of iron per c.c., the second from ferrous chloride containing 0148 gram of iron per c.c., the third from ferric sulphate containing 0105 gram of iron per c.c., and the fourth from an alcoholic solution of ferric chloride. The curves all show about the same temperature coefficient at points corresponding to the same temperature.

The object of the present communication is to give an account of the chief results of an investigation into the processes connected with the formation and fertilisation of the oospheres and the germination of the spore in Ascophyllum, Fucus vesiculosus, and Fucus platycarpus. The more obvious details of development have been especially studied by Thuret, and later by Oltmanns. But neither of these writers paid any special attention to the behaviour of the cell-nuclei, nor did they succeed in observing the actual process of fertilisation. Behrens has communicated an account (‘ Ber. d. Deutschen Bot. Gesel.,’ Bd. IY) of some researches made by himself on the fertilisation of the oospheres, but we are unable to accept his conclusions for reasons shortly to be recounted.

The material for these investigations was obtained in London from Bangor, Plymouth, and Jersey, but it was compared with other material collected and fixed at the seaside at Bangor, Weymouth, and Criccieth. Furthermore, all the growing apices and conceptacles for sectioning were collected by one of us directly at the three last named places. Some samples were gathered between the tides, and fixed at once, others were first kept for a time in salt water; the best results, however, were obtained from plants collected in a boat about two or three hours after the tide had reached the plant, and also from other plants taken a short time before they were left exposed by the ebb tide.

In order to study the fertilisation and germination stages, male and female plants were kept in separate dishes, and were covered over so as to prevent drying up. This method gave far better results than those more usually advocated. On the appearance of the