252 The Botanical Gazette. [June, 
Darwin and Wiesner (Die heliotr. roy wrod 1878-80), namely, that 
heliotropic movements may become fixed by growth. 
That growth is rhythmic, and not contin sits was known already to 
Ingenhouss and Th. de Saussure. We know that “growths that start 
together” are by zo means likely to rest together, for Fe the 
question of individual differences has never been much studied, we 
are, in our studies, always troubled with individual vatiattone 
The cause of the polarity is light; polarity may be changed, in 
growing leaves, into the fixed, normal light-position, when surround: 
Ings are chan ged; ¢ rown leaves will continually stay in the position of 
polarity. All that is needed to demonstrate this is a couple of drain 
S. 
II. The twisting of leaf-blades was investigated by Wichura (Flora, 
Pay 1852.); since which time, these movements have not been much 
stu 
,in monocotyledons, torsion of the leaves to the right age place, 
us; Tr 
Secale; Hordeum. Torsion to yet Aas occurs in Fritillatia; Allium 
(some); Festuca; Avena (upper le ¢ 
It has never been proved that orbit is the kcal ais of these 
moye ments, for an elimination of heliotropism by mea of the clino- 
stat has never been made. The twisting of leaves in Guanine is of 
much systematic value, and says ten times more than a thousand sy? 
onyms ina omaer ion. 7 CHRISTIAN Bay, ete — Lowa. 
sota. ‘Botanical Stu ’ 
As.edit itor of ‘Min eae Ratan Studies 1 regret. “shit my ey 
ould, even in a single case, fail tom j 
ee Bae & 3 
‘ 
of articles for. its. pages s 
tion of Mr 
me, through the Gaze ree suggestions ‘concerning Ww at 
enous maropriety publish in, the special journal en 
ported by a Minnesota enactment, since it is’a Minnesota it 
cee acts. to do and since it is the wish o Ufhnd mb Oat 
sent out price to whoever might be suppos 
hope no one will fee! etaned if ae of its articles, from his beady 
ene sont of view, seem too local and of too restricted inte 
pu 
In rep case in'hand, while Mr. Coville’s opinion, ot wet ttt bel 
nesota survey shonld publish at a given, moment a 
oS al ‘ « + 4 b an : 4 ould 
interest, I trust he will pardon me for suggesting that ae : 
unusual critical powers may be in danger of deteriora ott or 
