Page:The Journal of Indian Botany.djvu/148

118 As regards the position of the abnormal shoots on the plant no special relationship could be found. They occurred scattered on the plant. This point is also referred to take on in the paper.

The length of the needles of the abnormal shoots was also measured but no special relationship with the length of the needles of the normal shoots could be made out.

It will be seen from what has been described before that 4-leaved spurs are by far the most common of abnormal shoots in the seedlings of Pinus longifolia forming as they do 83'8 % of the whole lot of abnormal shoots. The actual numbers observed in one hundred plants were 145 out of 173. The numbers of 2-leaved and 5-leaved shoots were 17 and 11 respectively. (The normal number of leaves in the dwarf shoot is three and according to the observations of the writer variations in the adult plants is extremely rare.) The seedlings show therefore that a very great majority of abnormal shoots possess a larger number of leaves than the normal shoots. This is contrary to the observations of Thomson who says (Bot. Gaz., May, 1914) : — " It is more usual to find the spurs poorly developed when they first appear on the seedling .... This feature shows itself especially in species which have normally more than two leaves in the mature condition." Out of the 57 plants with abnormal shoots only two possessed 2-leaved abnormal shoots only, and tenmore which possessed 2-leaved shoots in addition to other forms of abnormal shoots did not show that the 2-leaved shoots were in 6very case the first formed abnormal shoots. In one the only 2-leaved shoots present was near the top above some other abnormal shoots, but in the other nine the shoots were near the base.

The writer is however in perfect agreement with the conclusion arrived at by Thomson when he says : "The lack of definiteness in the number of leaves in a fascicle, and the occurrence of supernumerary needles in the recognised primitive region and after wounding, are evidence of the branch character of the spur of the pines." He points out also that the normal proliferation of the spur in the seedling and young plant into an ordinary branch with both primordial and fascicled leaves, and the traumatic revival of this condition in the mature tree place this conclusion beyond reasonable doubt, strengthened as it is by the normal occurrence of the spirally arranged leaves in the seedling and other facts.

According to this view it would also appear that species of pine possessing a smaller number of leaves in their spurs are more specialised than the others and the tendency has been towards forming spurs with fewer and fewer leaves. This conclusion is also supported by the facts reported by Boodle (New Phytologist, 1915):—"In