Effect of Environment on the Hypocotyl 
in the Genus Luzula. 
BY 
W. EDGAR EVANS, BSc., 
CARNEGIE SCHOLAR IN BOTANY. 
With Plate XXII. 
I have thought it best to divide the contents of this short 
paper into two parts; the bulk of the observations and descrip- 
tions forming the first of these, and the second containing a few re- 
marks on the minute anatomy of the hypocotyl. My best thanks 
are due to Prof. Bayley Balfour, under whose supervision the work 
has been carried out at the Royal Botanic Garden, Edinburgh, 
for the facilities he has at all times allowed me, and for help in 
many other ways. 
PART I. 
On comparing some seedlings of Lusula purpurea, Link,, 
germinated this spring with a series collected from a sowing made 
last year, I was struck by a marked difference in the appearance of 
the seedlings in the two gatherings. In both cases the seed had 
not been separated from the capsule, or from the flower perianth 
enclosing it ; and it was owing to this fact that my attention was 
at first arrested, The seedlings germinated last year corresponded 
to the description given by Laurent (1): the green cotyledon 
bearing on its apex the seed, along with the first foliage leaves 
formed a rosette, while the primary root arose almost directly 
below this, owing to the extreme shortness—amounting almost 
to absence—of the hypocotyl. The remains of the perianth and 
(Notes, R.B.G., Edin, No. XVIII., August 1907.) 
