1922-23.] BOTANICAL SOCIETY OF EDINBURGH 163 



There is one point of more than ordinary interest about 

 the germination of Salix as described in the foregoing para- 

 graphs. Mr L. B. Stewart, Royal Botanic Garden, Edinburgh, 

 has tried to germinate willow seed of most of the British 

 species, during the last twenty years, and until now has had 

 to confess failure. It was he who first drew my attention to 

 the seedlings, and to him I am indebted for specimens. The 

 seed used on this occasion was gathered by Dr. M. \Vilson 

 early in October from a tree near Bavelaw. on the edge of 

 Balerno Moor. A second sample gathered from the same 

 tree a fortnight later germinated just as successfully as the 

 first supply. Both samples were collected in perfect condition, 

 just as the seed was escaping from the capsules. Since the 

 seeds are minute and since the embryos are green, it seems 

 not improbable that immediate sowing is necessary to ensure 

 germination. The seed did not receive any special treatment. 

 It was grown in a pit at 60°-65'' F. and germinated fairly 

 freely in sand, in soil, and on moist filter paper. Another 

 visit to the tree about 18th November resulted in the dis- 

 covery of some seedlings germinated under natural conditions. 

 These had just attained the expanded cotyledon stage shown 

 in fig. 10. 



There is a record by Sir John Lubbock (On Seedlings, 

 vol. ii, p. 542) of the germination of two species of Willow, 

 S. cinerea and S. repens, a seedling of the latter being figured. 

 Comparison of the measurements of *S. repens seed with those 

 given in his account indicates that the cotyledons grow to a 

 considerable extent in that species. No such growth could be 

 determined in the case of S. pentandm. 



EXPLANATION OF PLATE VIII. 



Figs. 1-10 are ten times natural size ; fig. 11 twice natural size.. 



Fig. 1. Seed of Salix imntandra with aril. 



Fig. 2. Seed with aril removed. 



Fig. 3. Embryo removed from seed coat. 



Figs. 4-11. Stages in germination. 



Fig. 4. Seedhng five days after germination. 



Fig. 10. Seedling five weeks old. 



Fis;. 11. Seedlins; seven months old. 



