THE PKOTOPLAST AS HOUSE-BUILDER 



49 



to practical account. An Imperial sugar factory was then established at 

 Rambouillet : pupils were regularly instructed in the process ; premiums 

 were offered for the best samples of the new sweetener ; and, in the course 

 of three or four years, the manufacture of beet-sugar was prosperously 

 set on foot. Canose occurs abundantly in the Sugar-cane (Saccharum 

 offlcinarum') and 

 S uga r-m aple ( A cer 

 saccharinum), and is 

 the substance found 

 in the nectaries of 

 nowers out of which 

 the bees make their 

 honey. Itis 

 secreted by the 

 protoplasm of the 

 cells composing the 

 nectaries, and the 

 quantity is at its 

 maximum during 

 the emission of the 

 pollen, but ceases 

 when the fruit is 

 formed. Its pur- 

 pose is evidently to 

 attract insects or 

 small birds to the 

 plant, and thus to 

 secure pollination 

 a subject of deep 

 interest, which will 

 be considered more 

 fully farther on. 



Canose, or Cane- 

 sugar, must be care- 

 fully distinguished Flo> 74 ._c EL ANDiNE (Chdida 

 from Glucose, or 

 Grape-sugar. The 

 formula of the first- 

 named is C^H^On, of the latter C 6 Hi.,0 9 ; and glucose, as we have already 

 seen, is a result of chemical rather than of protoplasmic action (p. 44). It 

 gives a bulky yellow precipitate with the reagent known as Fehling's 

 solution, which Cane-sugar does not. 



No account of the peculiar juices of plants would be satisfactory which 

 excluded a reference to the milk-sap, or latex. This fluid, though clear 

 7 



Photo by] 



A plant that must not be confused with the Lesser Celandine, which is not related. The 



Celandine is a member of the Poppy family. Its sap is milky but of a yellow colour. 



EUROPE and w. ASIA. 



