140 BOTANICAL GAZETTE | [FEBRUARY 
Test tube no. 1-5 cc. starch paste plus 1 cc. algal extract 
sé “cc “cc 2-5 cc; ‘é 6é it Ic ce “ce 
“a 
eee. ero ee, commercial diastase 
“ce ce ce ce te “ce ce 
4-5 CC. 2 cc. 
ek eh ner ace ae Se distilled water 
‘“ ‘“ ‘ 6-5 cc. 3 ec 73 
Bot Oe ee ee, wntreated age paste 
To ot eee OC, algal extra: 
solut 
eo ee Oe, Baa paceta ition 
When the experiments were to run for a longer period, the 
amounts were increased, but the same proportions were maintained. 
At the end of certain periods, indicated in the tables, 2 cc. of the 
solution were taken from tube number one and placed in two 
smaller tubes, 1 cc. in each tube. This process was repeated until 
test samples had been taken from each of the 7 tubes. One of 
each pair of small tubes was treated with iodine and the other with 
Fehling’s solution. The experiments were all kept at room tem- 
perature, which was rather low, the daily average being 18°6 C. 
B. Digestion in Van Tieghem cells 
To determine microscopically the effect of the algal extract 
upon unboiled starch, small quantities of dry corn starch were 
placed in four Van Tieghem cells. Three of these were treated 
with extracts from Polysiphonia, Agardhiella, and Ceramium, the 
fourth with distilled water to act as a control. 
7. TERMS USED IN TABLES TO DESIGNATE COLOR REACTIONS AND 
AMOUNTS OF PRECIPITATES 
That the standard for the designation of iodine color reactions 
and for the amounts of copper precipitate might be as nearly as 
possible the same for each series of experiments, two sets of terms 
were adopted. These may be interpreted in the following manner 
by referring to PRANG’s Standard of colors (1898): 
IODINE COLOR REACTIONS 
As specified in tables As illustrated by chart 
t, Blue... oo. ee Plate I, 1-B 
2. Tinge of mile Ue “1 eey 
3. Dineen i ey 
he. SUEPIe ee es ae erie kOe ee we hai ee ee ge 5 oS i Ul, 1-V 
ree WONG ais ges ieee eae ee pe Fig 
6. Very light purple... 1 a 
7- WE oo a ce ae eta ee ee ee Caneel wee ee ens ag Vv; 5-0 
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