84 KJELLMAN, THE ALG^ OF THE ARCTIC SEA. 



cially for the purpose of assimilation. These facts can and certainly ought to be 

 explained in the following way. In its original home, the Arctic Sea, this plant has 

 need of the whole year, and, during that time, of all its assimilating organs in order 

 to accomplish its development; whereas on the coast of Bohuslan, where it has come 

 into more favourable conditions, it is able, by carrying on assimilation for only a part 

 of the same time, to form such a quantity of nutrient substances as suffices not only 

 to develop the reproductive organs, but also to supply the assimilating organs, that 

 it has cast off after they have functioned during the necessary time. 



With regard to the physiology of nutrition, the arctic algas are in several respects 

 most instructive. They may during very long periods be inclosed in ice and exposed 

 to high degrees of cold, without being killed or losing their power to resume vigorously 

 their development, when the hindering fetters have been broken. Still more, they 

 prove that plants can germinate at a temperature of from — 1° to — 2° C, and are 

 able, without being checked in their vital functions by the temperature scarcely ever 

 rising to the freezing-point, to develop into magnificent forms producing endless masses 

 of reproductive cells throughout all the year or during the greater part of it. We 

 have thus in these algae vegetative organisms whose optimum of temperature may be 

 stated to be about or below zero C. Besides, the energy of assimilation requisite for 

 this rich and vigorous development seems to comport very ill with the slight quantity 

 of light afforded to these plants. As far as I can judge, this cannot be explained 

 otherwise than by the assumption that the arctic algse in general are content with a 

 very inconsiderable measure both of light and of warmth. 



With the modern theories on the nature of the process of assimilation, it is cer- 

 tainly difficult to assume that the algae should continue uninterruptedly their assimi- 

 lation at the 80:th degree of latitude during the winter when there prevails an almost 

 absolute darkness to the human eye; but such an assumption becomes almost necessary 

 on account of the rich and vigorous development of new parts that was proved to take 

 place during the winter. Otherwise one would be obliged to assume that the consi- 

 derable quantity of plastic substance used up by the algae in forming new organs 

 on a large scale during the dark season, are nutriments stored up in reserve du- 

 ring the preceding period of light. I cannot affirm decisively that this was not the 

 case. But on the materials that I have had at my disposition, such an assertion cannot 

 be founded. Certainly, several Florideae contained a remarkably large quantity of solid 

 substances in their cells during the winter. But neither in the Fucoideae nor in the 

 Chlorophyllopliycece such stores were to be detected. However, nutrient substances in 

 reserve may have occurred in them in a liquid form. I had no means of investigating 

 this 0- If the raw materials are assumed to have been gathered during the light season, 

 this implies, on the other hand, that nutritive substances must be prepared then to an 

 extraordinary extent, as not only all the material is to be formed of which vegetative 

 organs are built, but also a sufficient quantity is to be reserved for the developing of 



1) It ought to be remarked here that the observations to which I refer chiefly, were carried on during an in- 

 voluntary and unpremeditated wintering on the north coast of Spitzbergen. 



