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 Bohuslin, 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 alge 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 alge 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 alge 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 alge 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 alge 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. JI 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 Floridez contained a remarkably large quantity of solid 
substances in their cells during the winter. But neither in the Fucoidex nor in the 
Chlorophyllophycee 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'). 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. 
