TRANSACTIONS OF SECTION K. 707 
chloric acid, and after repeated washing of the humic acid adding just sufficient 
ammonium hydrate to dissolve it. This was then diluted with distilled water 
in the proportion of 1 humate to 200 water. 
Maize seedlings, obtained by germinating maize seeds in moist sand and 
when the roots were a few inches long cutting off the seed, were used for four 
series of culture experiments, two plants in each series. After six weeks’ 
growth the following results were observed :— 
Series 1.—Distilled water. Plants died. 
Series 2.—Ammonium humate alone. Plants grew well in this at first; later 
showed signs of starvation. Root development very strong, equal to roots 
in normal culture solution 15 to 25 cms. long. 
Series 3.—Ammonium humate with phosphates and potassium. Plants 
showed stronger growth than those in normal culture solution, being taller and 
having stouter stems and larger leaves: The root development was remarkable. 
The majority of the roots were 30 cms. long and five roots measured to 45 cms. 
each. 
Series 4.—Normal culture solution (Detmer). Plants made healthy normal 
growth. Roots 15 to 20 cms. long. 
This effect, of ammonium humate on the development of the root system and 
the general growth of plants has been further demonstrated by a series of 
experiments on pelargoniums, salvias, carnations, begonias, and balsams at the 
Royal Gardens, Kew; and on wheat, barley, oats, radish, turnips and tomatoes 
at Chelsea Physic Gardens. ; 
3. Juvenile Flowering in Eucalyptus globulus. 
By Professor F. EB. Werss, D.Sc. 
Cases of juvenile flowering are known for quite a large rumber of plants, 
some of the most striking instances recorded being in the genus Rosa, in which 
seedlings still in possession of their seed-leaves bear a terminal flower on a stem 
not more than a few centimétres in height. Cockayne has recently drawn 
attention to numerous cases of juvenile flowering met with among New Zealand 
plants; and Diels, in his interesting book on ‘ Jugendformen und Bliithenreife,’ 
gives instances of a number of plants, largely belonging to the Australian Flora, 
in which he has observed similar occurrences. In several cases Eucalypti, 
which usually show a marked difference between the foliage of the immature 
plant and the mature foliage, have been found in nature flowering on small 
shrublike plants still possessing leaves of the immature type. Thus the plant 
from Southern Tasmania, described by J. D. Hooker, under the name of 
Eucalyptus Risdoni, was regarded by von Miller, in his ‘ Eucalyptographia,’ as 
only a form of HZucalyptus amygdalina, differing from the latter only in the 
possession of broad sessile leaves of immature type. It has been suggested that 
the cooler climate of Tasmania prevents this species of Eucalyptus from growing 
to proper vegetative maturity. 
In a similar way Yucalyptus pulverulenta and Eucalyptus melanophloia seem 
to be juvenile flowering forms of Hucalyptus Stuartiana and Hucalyptus crebra 
respectively. 
I have so far not seen recorded the occurrence of the same phenomenon in 
Bucalyptus globulus, but during the past year a case has occurred in my green- 
house. A young plant of this species, growing in a six-inch pot, was cut down 
after its first year’s growth to the height of about two feet. One of the 
lateral buds then grew out and became the leader, developing in the autumn 
a number of flower buds in the axils of five pairs of leaves of the type usual 
to young plants—namely, broad and rounded at the base, bilaterally symme- 
trical and covered with bloom. During the winter the buds grew normally to full 
size, and the flowers of normal size opened during the month of June, when the 
plant was little more than two years old. Several of them were fertilised and 
have set seed. It is of interest to note that in the same greenhouse a plant 
which has been grown freely for many years has produced neither flower buds 
nor mature foliage. On the other hand, a plant two years of age, of which the 
main stem was cut back this spring to the dormant axillary buds of the cotyle- 
dons, threw up two shoots from these buds, one of which beeame a leader, and 
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