£890.] Botany. 577 
This latter mineral is pleochroic in blue and green tints, while the 
former is pleochroic in brown and brownish red tints. Barkevikite is 
an essential constituent of the augite syenite occurring between the 
fjords of Christiania and Langesund.——Sfangolite is proposed by 
Penfield? as the name for a hydrated sulphate and chloride of copper, 
occurring, probably, somewhere in the Globe District, Arizona. The 
new mineral incrusts cuprite, and is associated with azurite and ataca- 
mite (?). It is rhombohedral, with its crystals bounded by oP and a 
series of pyramids of the second order. The cleavage is perfect par- 
allel to oP. Etched figures produced on the basal plane by the use 
of dilute acids are bounded by oP and scalenohedral faces. The 
are all very clear, and all have an undoubted rhombohedral sym- 
metry. By reflected light the mineral is dark green, while by trans- 
mitted light it is light green. Pleochroism is slight. The double 
refraction is strong and negative, with a=1.694, e==1.641. Hardness 
on oP is 2, and on the pyramidal faces 3. Specific gravity is 3.141. 
The average of four analyses gives: 
SO, Gis ALO- Cuo- ILO 
roit Afri G60 costr dot 
corresponding to Cu,AICISO,+-9H,O. 
BOTANY. 
Some Reasons for Varieties not soon Wearing Out.—The 
direct result of a union of two or more distinct protoplasmic masses, in 
plant life, is a condensed, inactive, and transportable condition of the 
life of the species, that is, a seed or spore. Among lower plants this 
reproductive union usually takes place in the simplest manner, and at 
times that are determined by unfavorable circumstances for a further 
continuance of the life of the species in its ordinary rapidly-growing 
condition. Thus the moulds form their resting spores when the pros- 
pects are that resting spores will be most needed to carry the life of 
the species over the approaching period of cold, drought, or lack of 
food supply. The uniformity of the coming and going of the seasons 
has its parallel in the uniformity with which the higher plants produce 
their annual crop of seeds, In the great struggle for life that is going 
on, it is perhaps true that some species have found it to their advan- 
tage to form their seed early, and long before the time when the season 
3 Amer. Jour. Science, May, 1890, p. 370. 
