NEEDLES IN SPURS OF PINUS LONGIFOLIA.
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Pinus monophylla the spur shoots as a rule bear each a single needle, but two are occasionally present. Masters found by studying early stages that two leaf-rudiments are always produced, but that one of them generally becomes arrested at an early stage."
A paper on the comparative anatomy of the needles of the seed- lings and mature plants is in preparation.
The main conclusions of the paper may be stated as folllows:—
- 1. Spurs with more or less than three needles in the adult
plants of Pinus longifolia as seen in Lahore are extremely rare.
- 2. Spurs with more or less than three leaves are very common
in seedlings. Fifty-seven per cent, seedlings possesses such abnormal spurs.
- 3. Spurs with 4-leaves are the commonest of all, being 83.8% of all abnormal shoots.
- 4. The conclusion is drawn from these facts that a 3-leaved spur has been derived from a spur with more leaves, that the spur is equivalent to an ordinary shoot and that pines with a small number of needles in their spurs are more highly specialised than species with a larger number of needles.
