120 THE JOURNAL OF INDIAN BOTANY.
basis that a leaf cluster appears every other year the age of a leaf cluster would thus be from four to six years.
Ovules of Cycas Revoluta.
As has been mentioned above there are no male plants of Cycas revoluta anywhere near Lahore. Naturally therefore one would not expect ripe seeds on the female plants. It is interesting to note however that ripe ovules, with fully formed endosperm and archr- gonia but without embryos, do occur occasionally. Le Goc has studied the same phenomenon in Cycas Bumphii in Ceylon. (Ann. Roy. Bot. Gard. Peradeniya, 1917, 6). He also finds well-developed ovules in that species though he did not see any male plants in the locality. He thinks that the development of the ovules is due to the influence of foreign pollen which he found in the pollen-chamber, obviously implying that the presence of the pollen grains is necessary not only for the formation of perfect seeds but also for the full development of the ovules. Without going into a discussion of this question it may be stated that in Lahore a very great majority of the ovules of Cycas revoluta shrivel after some time and only a few occasionally develop the endosperm and archegonia. It has not as yet been determined whether they receive any foreign pollen or not. There are a few male and female plants of Zamia growing near these plants of Cycas revoluta and a male plant of Cycas circinalis is growing in a tub at some distance. Although the female plants of Zamia do produce a few ripe ovules and seeds, the female plants of Cycas circinalis growing in the garden have not so far been seen to form ripe ovules or seeds. The connection of the development of the ovules of Cycas revoluta with foreign pollen, if any such connection exists, will be investigated at an early date.
The ordinary ovule of Cycas revoluta which has not fully deve- loped is more or less spherical with the sides flattened or depressed and possesses a notch at the tip. The ripe ovules met with on the same plants are very much larger, do not show any flattening of the sides, and but are rounded and gradually taper towards the apex which is very distinctly acutely pointed. This last character is very curious especially because in the ripe seeds obtained from Japan the tip shows the usual notch, or at least there is no tapering at the upper end. {Vide fig. 1.)
Another interesting point in this species is the occurrence of in- termediate forms between the sporophylls and the scales. The sporo- phylls, as is well-known, are pinnately divided organs in which the lower pinnae are replaced by ovules and thus correspond to the foliage leaves, but of course are smaller, brown and whoolly. The sporophylls
