38 BULLETIN OF THE BUSSEY INSTITUTION. 
The experiment with the pine seeds was repeated at once quali- 
tatively and the result above stated was practically verified, for 
only small traces of mannose could be detected, and that after 
much trouble. ‘The qualitative test was more severe than the 
other, in that the product of the hydrolysis was evaporated to 
dryness, whereas in the quantitative test the partially evaporated 
liquor was treated. In this qualitative experiment 18 grm. of 
the powdered seeds were hydrolyzed, the neutralized product of 
the hydrolysis was evaporated to dryness, and the residue taken 
up with 20 cc. of water. When as much as 3 cc. of this solution 
were tested some crystals of mannose-hydrazone were finally 
obtained, after much waiting and, so to say, coercion; but when 
quantities no larger than 1 cc. of the liquid were examined the 
tests were less satisfactory, and no indications at all of the 
presence of mannose-hydrazone were got when the unevaporated, 
neutralized product of the hydrolysis was tested. 
The examination of the seeds of the Norway spruce, as pre- 
viously mentioned, was made for the express purpose of .confirm- 
ing or refuting the results of the tests made with the seeds of the 
white pine. As will appear from the following statement, the 
results of the trials with the spruce seeds were almost absolutely 
similar to those got with the pine seeds. Twenty-five grm. of 
the spruce seeds were boiled for three hours with 220 ec. of 
hydrochloric acid of 5 per cent., the acid was neutralized with 
sodium hydroxide, and tested with the phenylhydrazin reagents. 
No evidence of mannose was detected in the unevaporated liquor, 
while a few mannose-hydrazone crystals from one portion of the 
evaporated liquor and none at all in trials made upon two other 
portions of the liquor. Manifestly, there was but little mannose 
obtainable from these seeds. 
_ With regard to the quantity of mannan in the trunk-wood, it 
would of course be wholly improper to argue from the results of a 
couple of experiments that there is usually more mannan in the 
pine tree in August than in December; but the results above 
given point to the necessity of studying more carefully than has 
been done hitherto the general question as to the times and 
seasons when the pine and other evergreen trees store up their 
reserve food. 
