at different periods of the Day. 



the latter author states, his own observations and Hartings are 

 essentially the same, I may be permitted to quote the one as 

 representing the views of the other. Miinter says that he found 

 the diminution of light increase the growth of the branches of the 

 Sycamore, the Vine and the Elder. And this is precisely the 

 common opinion. But it will be seen from what has been just 

 stated, that in the four cases now mentioned, and under their 

 peculiar circumstances, that was by no means universally the case, 

 for in the Willow the greatest growth took place between 6 in the 

 Morning and Noon, of the Passionflower between Noon and 6 in 

 the Evening, and it was only in the case of the Vine and Fig that 

 the dark hours gave the greatest amount of extension. It is how- 

 ever to be observed that Munter's experiments were made in the 

 open air, and therefore may not perhaps be quite suited for com- 

 parison with those now detailed. 



The period when the Willow and Vine grew slowest was the early 

 Morning in the case of the Willow, and before midnight in the 

 Vine : the difference in the Willow being as 9.37 to 11.13 and of 

 the Vine as 16.02 to 18.13. This seems to show the danger of 

 employing a high Night temperature, which must necessarily force 

 such plants into growing fast at a period when nature bids them 

 repose. In the Fig the smallest growth was made in the early 

 Morning, but the rate of growth of that plant does not appear to 

 be materially different at any period of the day ; for, in nearly two 

 months, Night, when it grew fastest, had not an advantage over 

 Morning when its growth was slowest, to the extent of much more 

 than \ an inch. In the Passionflower the fastest growth was in 

 the Afternoon, the next at Night, and the smallest in the Forenoon, 

 in which respects it is at variance with all the others. 



Table 5 also seems to indicate the existence of some regular al- 

 ternation of growth, from fast to slow ; the morning growth of 49.87 

 diminishing at the next period to 46.66, then rising to 55.11, and 

 then falling to 49.16, which again rises to 49.87 ; and it is not im- 



