146 
As regards phenological observations, | may mention that 
Harrz found that, at Scoresby Sound, Diapensia opened-both 
flowers and leaves-on June 12th; and Vannôrrex in 1893 found 
that at Karajak (West Greenland) it opened on June 13th.! 
According to my investigations, fertilisation and embryogeny 
must certainly often take place long after pollination. 
The capsules may remain upon the plants far into the next 
vegetative period. The seeds are probably scattered very slowly. 
I have found a well-developed embryo in the latter. 
B. The Anatomy. 
W. Grever has studied the anatomy of Diapensiaceae and 
has given what appears to be a very thorough and exhaustive 
description of the anatomical structure of Diapensia lapponica, 
except that of the root. For all details of a systematic-ana- 
tomical nature the reader should refer to this paper, to which 
I can make but few additions; my aim here is to direct atten- 
tion to those features of its anatomy which are of especial 
value to it in relation to climate and other external factors, 
The leaf. (Figs. 4 and 5). The epidermis of the upper and of 
the lower surface is very much thickened, especially that of the 
upper surface. A very thick cuticle occurs everywhere, but it is 
thicker on the upper surface, and is there characterized by 
not being of the same thickness everywhere; it sinks at times 
into depressions of the cellulose membrane. The whole of the 
external surface of the cuticle is wavy. In the outer walls the 
layers beneath the cuticle (in both the upper and the lower 
epidermis) are not quite evenly deposited; there occur, especi- 
ally towards the lateral walls, canals which extend from the 
interior outwards towards the cuticle, without, however, reaching 
the latter. 
1 Cf. A. CLEVE, 1901, p. 41. “Auf dem Plateau in Knospe und Blüte “/6, 
in voller Blüte, ausserdem mit Knospen und verblüht *’/6; Kronenblätter 
meist weg */7; Früchte aufgeschwollen noch nicht reif lo.” 
