456 



Concerning the flrst of these points, however, I cannot for 

 the present communicate any results, in the luture I hope to 

 be able to do so. A priori we may venture to think that P. vil- 

 losa, if cultivated in Denmark, will continuously retain its arctic 

 type, being undoubtedly, of the three species in question, the 

 oldest inhabitant of arctic countries, and in herbarium material 

 I never, even far down in Sweden, perceived 

 any trace of development of an autumn- 

 rosette. With respect io P. alpina there is 

 nothing interesting to slate on this point, 

 but as regards P. vulgaris, the result of 

 its cultivation is subject to greater doubt, 

 and in consequence of this, such experi- 

 ments with this species have a greater 

 value. Whether the arctic type here is 

 constant, it is quite impossible to say, 

 though probability tends to the contrary. 

 Concerning the determination of a 

 geographical limit, I have been more 

 successful. P. vulgaris being a circum- 

 polar species, one would with such a 

 pliyto-geographical line (a sort of Biocho- 

 rus) be able to state the influence of the 

 arctic climate upon a particular plant, 

 and such a result would not be without 

 interest. A line of this sort must na- 

 turally be exceedingly dilQcult to draw; in order to be able to 

 arrive at a satisfactory result a great many observations in 

 nature are required, made mainly in July or August. Only when 

 this has been done in regard to the main points, will it be 

 possible to proceed to the determination of the climatic factors 

 distinguishing the two types. 



If we take the opposite view and draw the geographical 

 limit on the basis of the already existing climatological material, 



Fig. 4. 



Pinguicula аЦппа. 



Autuinn-rosRtte is deve- 

 loped; the fruit-stalk is 

 pushed somewhat to one 

 side by the rosette. Pla- 

 teau de Murnau (Haute 

 Bavière). June. About Vs 

 natural size. (H.E.P. phot.) 



