TEACHERS DEPARTMENT. 
85 
determine the points of the compass. ■ Lately, further investigation 
of this matter shows that the mosses grow by preference on the 
sides of the trees which, for one reason or another, are least likely 
to lose their moisture. On horizontal branches, the mosses usually 
grow on the upper side, because the water remains there most 
readily. The bases of the trunks are more moss-covered because 
they receive a larger quantity of water. The unequal distribution 
of light also plays a part.— (Science, 17 Feb., 1905.) 
Stipules in the Cultivated Rubber Plant. —All who have 
grown the ordinary rubber plant are familiar with the white or 
red membranous hood which clothes the terminal bud. That this 
is made up of two connate stipules is evidenced by the occasional 
appearance at the tip of the hood of two points, the apices of 
the two elements. This hood, the insertion of which extends 
quite around the stem., persists until the unfolding of the blade 
of the leaf next above in position. In the young shoots which are 
forced to grow by cutting back the stipules, which of course en¬ 
close the terminal bud, are for some time quite distinct, each mem¬ 
ber of a pair being slender and not at all connate with its mate, 
a condition which may be regarded as nepionic—-that is, probably 
represents the primitive stipular condition in the plant in question. 
As the new shoots continue to develop the stipules later produced 
are connate, and so conform to the mature type. 
C ar d amine chenopodiifolia is a South American species which 
produces hypogaeous flowers and fruits, as well as those of the 
ordinary type. This dimorphism is explained by O. E. Schultz* 
as an adaptation of the plant, not to- the unfavorable climatic con¬ 
ditions, as was held by Griesebach, but as a means of propagation 
which, by position, protects the plant from the danger of eradica¬ 
tion by grazing animals. 
The material which is usually lacking from the supply of 
forms for laboratory work' is that representing the families of 
plants whose -flowers appear earliest in the year. Now is the 
time to lay in a supply which may be preserved for future use. 
For small and delicate flowers strong alcohol is best and they 
should not be crowded in too tightly. ■ For others which are not 
* Monographic der Gattung Cardamine. Botan. Jahrb. 4: 32. 1903. 
