176 
ALFRED DACHNOWSKI AND R. GORMLEY 
interest in the case of heaths and other bog plants having mycorrhiza, 
since we have no knowledge of the form of organic peat constituents 
which they can assimilate. 
In the continuation of this work the same general methods described 
in previous publications have been used. For the glycocoU employed 
in these experiments we are indebted to Prof. W. McPherson, of the 
department of chemistry of this University, whose interest in this 
problem has been voiced in his vice-presidential address before section 
C of the American Association for the Advancement of Science (lo). 
^ Grammolecular solutions of varying concentrations were prepared in 
distilled water which had been filtered through carbon (lamp black). 
The experiments were begun in October, 1913. The bog plants used 
in these tests were obtained, in November, 1913, from the cranberry- 
sphagnum association on Cranberry Island at Buckeye Lake, Ohio.^ 
With the exception of wheat, these and all other plants used were 
cuttings of known green weight. The plants were freed from dead 
material, washed repeatedly in distilled water, fastened to sterilized 
perforated corks by means of absorbent cotton, and transferred to 
sterilized, wide-mouthed, paper-covered glass jars of 500 cc. capacity. 
No other precautions were taken against the presence of nitrifying or 
other organisms. Although sterilization was imperfectly maintained, 
the results obtained with the selected series are fairly satisfactory. 
Each experiment was continued for 7 to 14 days, according to the 
amount of water transpired before renewing the culture solution. The 
different cultures always stood side by side in the university green- 
house. A record was kept of the weight of water absorbed and the 
quantity transpired. The difference between the initial and final 
green weight of the plants was taken to represent the amount of growth. 
The original intention, to show what quantities of glycocoll are 
assimilated directly and thus increase the dry weight of plants, could 
not be adhered to in this series of experiments. Arrangements have 
been completed whereby the biochemical investigations of the problem 
will be carried out as soon as the improvements in the equipment of 
the new laboratory devoted to this work have been provided. For 
the present only a few of the preliminary experiments are here grouped 
according to the response of the plants and indicated by data on trans- 
piration, amount of water absorbed and retained, and the gain or loss 
in the weight of plants. Related data from experiments with cuttings 
2 Geol. Sur. Ohio Bull. 16: 239. 
