463 



this species my temperate and arctic types show a one phyto- 

 geographical scheme. Through a single period of growth the 

 picture will be as follows: 



I. Subtropical type. P. caudata. Mexico. Summer-rosette 

 of the ordinary Fingidcula-lype, terminating in a flower. The 

 rejuvenating shoot in the axil of the uppermost foliage-leaf 

 forms a winter-rosette like that of Sempervivum with short and 

 thick leaves, filled with amylum and furnished with a large 

 layer of cells filled with water. The glands are not fully 

 developed. (Nourishment by insects is thus excluded in the 

 winter-rosette). By this peculiar winter-rosette the plant passes 

 the unfavourable season. Hibernacle is never developed. Ac- 

 cording to Sander also the winter-rosette can develop flowers. 

 ^Literature: Schlechtendal, 1832, p. 393. De Candolle, 1844, 

 p. 28. Sander, 1881, p. 541. Hooker, 1882, pi. 6624. Gode- 

 froy-Lebeuf, 1883, p. 387. Dcchartre, 1887, p. 207). 



II. Temperate type. P. alpina and P. vulgaris. Spring- 

 rosette, terminating in a flower. The rejuvenating shoot in the 

 axil of the uppermost foliage-leaf develops an autumn-rosette, 

 in the middle of which the winter-bud is to be found; both 

 rosettes are of the ordinary Pinguicula-tyT^e. 



III. Arctic type. P. vulgaris (arctic specimens) and P. 

 villosa. Spring-rosette, terminating in a flower. The winter- 

 bud is directly formed from the rejuvenating shoot in the axil 

 of the uppermost foliage-leaf. Autumn-rosette does not develop. 



The three types, here mentioned, show the main characters 

 of the forms produced in different climates; between the two 

 first I am not able to demonstrate a transition. But I see an 

 evident transition between the two last types in P. vulgaris. 



Also in the rare P. vallisneriae folia there seem to be 

 circumstances, worthy of closer investigation with regard to the 

 shoot-structure. The literature, however, gives but few and 

 uncertain indications on this interesting point. (Webb, 1863, 

 p. 48. BucHENAD, 1865, p. 62.) 



