SOME OBSERVATIONS ON CYOAS IN LAHORE. 119 



year and still older ones produce clusters every other year or even 

 at longer intervals. It may be mentioned also that it is difficult to give 

 the exact age of the plants as the time during which the buds had 

 remained attached to the parent plants is not known. 



Another series of observations was undertaken on four large 

 plants growing in the Botanic Garden. These are certainly more than 

 twenty years old at the least. All of them produced cones in May 

 1919, and the following measurements were taken in October 1919. 

 The girth is about the same throughout the whole length of the stem 

 except at the very base where it is a little smaller. 



Height to top Height to lowest Girth about middle Circumference of 

 of cone. ■ green leaf. of stem. cone. 



1. 3 ft. 2 in. 2 ft. 3 ft. 5 in. 3 ft. 3 in. 



2. 4 ft. 3 in. 2 ft. 10 in. 3 ft. 6 in. 3 ft. 3 in. 

 3 3 ft. 5 in. i ft. 3 in. 3 ft. 2 in. 3 ft. 1 in, 

 4. 3 ft. 1 in. 1 ft. 10 in. 3 ft. 5 in. 3 ft. 3 in. 



The trees were kept under observation from October 1918 to 

 November, 1920. The following was the sequence in which the 

 foliage leaves and sporophylls were arranged with the time of appear- 

 ance where known : — 



May, Oct. 



1919. 1919. 



Spor. 



Spor. 



Spor. 



Spor. ... Fol. 



The number of foliage leaves in each cluster was usually about 

 sixty, and the number of sporophylls in each cluster varied between 

 120 and 170. It will be seen that there is no invariable alternation 

 between the foliage leaves and the sporophylls though in many cases 

 it is distinctly present. Again a cluster of foliage leaves appears 

 usually after about eighteen months, though a cluster of sporophylls 

 appears before the second foliage cluster in the meantime. We can 

 say that usually one cluster appears every year whether of foliage 

 leaves or sporophylls. Plant No. 2, however is very curious in this 

 respect. It produced a cluster of foliage leaves in April and imme- 

 diately after that a cluster of sporophylls about the end of May. 

 Even now its activity was not quite exhausted and it produced an- 

 other cluster of foliage leaves in November, 1920 when the other three 

 trees showed nc sign of forming any leaves. This behaviour is quite 

 unusual but the cause of this excessive activity is not known. 



In No. 4 three clusters of green leaves were visible below the 

 cone, but in the others only two such clusters were present. The 

 leaves below them had all died and therefore been cut away. On the 



