426 Meyen’s Report for 1839 on Physiological Botany. 
given. Finally, the curious increase by continued regular di- 
vision was explained in the case of that small Alga which I 
have denominated Merismopedia punctata, a plant which 
Ehrenberg has erroneously reckoned among animals. The 
regular position of the small ellipsoidal cells of this plant in 
fours instantly strikes the observer, and the propagation of 
these takes place by their regular division, which by obser- 
ving different individuals may soon be seen in all its different 
stages. ‘The new cells group themselves always in fours, and 
are surrounded by a tender gum-like substance. 
In the Botanical Society of London* Mr. Daniel Cooper 
made known some experiments he had made to see whether 
coloured fluids entered into plants which were watered with 
them ; the experiments were made without the author’s being 
aware of what had been done previously. Three pots with 
large beans were taken, two were filled with mould and one 
with common sand, and all were watered with the same quan- 
tity of fluid, but the water which was used for the pot filled 
with sand was strongly coloured with madder. The result 
was that the coloured fluid did not pass into the plants, 
which were not at all changed by the operation. Mr. Cooper 
had placed one of the pots with mould in a dark place; he 
brought the grown-up plant into the light, and saw that the 
leaves first became lax and then died; and the same was the 
case with the other pot, which had been allowed to stand in 
the open air and was then brought into the dark ; in this case 
also death finally ensued. 
At the same time Mr. Cooper made known an observation 
of Mr. Wilkinson, who had observed that a potatoe which 
had fallen into a well twelve feet or more deep, grew out of 
it in order to reach the light. According to other observa- 
tions, the length of a potatoe stalk grown in a cellar has been 
found to be twenty feet, on attaining which length it reached 
the window. 
PHAUNOMENA OF GENERATION IN PLANTS. 
1. In the Phanerogamic Plants. 
In the former Report I could only give a very imperfect 
account of M. Wydler’st research on the formation of the 
embryo in the genus Scrophularia, for up to that time the 
treatise was unpublished. M. W. made his observations on 
* Proceedings of the Bot. Society of London, &c. With Plates. London, 
1839. 
+ Recherches sur la Formation de l’Ovule et de !’Embryon des Scrofu- 
laires.—Bibliothéque Universelle de Genéve, Oct. 1838. 
