ZOOLOGICAL DEPARTMENT. 373 



different kinds of plants and also quite variable in the same kind of plants. In one 

 sample of nectar there was found to be 93 per cent of water while others were found in 

 which there was only a trace of water. The proportion of water usually varies from 60 

 to 85 per cent. 



The total quantity of sugar also varies greatly. The quantity of cane sugar is very 

 variable, according to Bonnier, in different kinds of plants. Its quantity also depends 

 upon the age of the plant. In general the nectars which are extrafloral contain less 

 cane sugar than the Moral nectars. The nectars of the Prunus avium and Crataegus 

 oxyacantha contain much less cane sugar than the nectar of the Vicia. The nectar of 

 the Calluna vulgaris contains an extremely small quantity of cane sugar. Cane sugar, 

 on the contrary, is extremely abundant in the nectar of the Mirabilis, Fuchsia and 

 Helleborus niger. From some of these plants Bonnier was able to separate the cane 

 sugar in a pure state by chrystallization. Some analyses of the nectars of different 

 plants made by Bonnier follow below: 



Nectar from, Lonicera periclymenum. 



Water 16.00% 



Cane sugar 12.00^ 



Reducing sugar 9.(X^ 



Dextrin, gums etc 3.00;^ 



Nectar from Lavandula vera. 



Water ,... 80.00$? 



Cane sugar 8.0(^ 



Reducing sugar 7.50^ 



Dextrin etc 4.50^ 



Nectar from Fritillaria imperialis. 



Water 95.00$? 



Cane sugar 1.00$? 



Reducing sugar 1.50^ 



Dextrin etc 2.50^ 



In regard to the analysis of honey, Bonnier says that good indications of the character 

 of the nectar secreted by the flowers might be given by the analysis of honey provided 

 the nectar did not suffer considerable modification in its passage through the organism 

 of the bee; but in general, cane sugar, which is quite abundant in the nectar, exists 

 only in very feeble quantities, or not at all, in the honey. He states, however, that in 

 honey from mountainous regions a considerable quantity of cane sugar remains. 

 (Possibly this honey was collected very rapidly, and so not fully digested by the bees. 

 A. J. C). Also honey harvested in different seasons presents very different character- 

 istics, which often recall the character of the nectar which the bees gathered at the 

 time. The quantity of saccharose in the nectar of the same species of flowers varies 

 within wide limits. In the floral nectaries the maximum proportion of cane sugar in 

 the tissues corresponds to the period when the ovary has reached its development and 

 the fruit has not yet commenced to develop. In all kinds of nectaries, the cane sugar 

 18 accumulated as the flower approaches maturity and begins to be destroyed as the 

 organs growing from the flower approach maturity. For this reason, when the amount 

 of saccharose iDegins to diminish the relative proportion of reducing sugars increases. 



It is not by any means certain, however, that at any time in the history of the plant, 

 the sugars might exist in the flower wholly as cane sugar. On the other hand, it is 

 well known that the juices of plants, in nearly all cases where they contain sugar, 

 contain mixtures of various kinds of sugars. 



Another reason, which makes plain the abundant appearance of cane sugar during 

 the progress of the life of the plant, is that the cane sugar itself is not directly assim- 

 ilable by the tissues of the plant, while the invert sugar is assimilable. The result 

 would be that there would be a tendency of the plant to remove from its juices the 

 invert sugar, while the cane sugar would be stored for subsequent employment. 



I am aware of the fact that botanists often speak of nectar as sugar, giving the 

 impression that it is cane sugar. Even Gray and Goodale speak of the specific gravity 

 of nectar, and assume that the sugar contained therein is pure cane sugar. 



5. It has long been admitted by European as well as American chem- 

 ists that some honey, especially that from the pine honey dew, was so like 



