Physiology of the Spermatozoa of Perns. 559 
-§ X Tcnnr m °l malic acid, and is apparently indifferent at 
a solution one-tenth as strong which in the case of malic acid 
gives a just appreciable reaction. 
With potassium nitrate I could detect no attraction at 
0-05 gm per cent., whereas there is a slight one at o-i per 
cent. The concentration necessary to give a just appreciable 
reaction lies then between ti^oVo an d l' olHh r m °l* Malic 
acid gives a just observable reaction at o-ooi gm per cent. 
TABLE III. Isotonic coeff. — 2. 
Standard solutions of 
Potassiuni nitrate 
J in parts of a mol 
| in grams per cent. 
1 
IO-I 
1 
ITT 
I-OI 
i 
IW 
0-1 
TTHTTF 
0*01 
10 0 00 
0-001 
TTnnn 5 ‘o 
0.0001 
Cane sugar 
C 12 H 22 O u 
34 2 
N 
O 
0 
O 
0 
0 
Grape sugar 
C 6 Hi 2 0 6 
180 
N 
O 
0 
O 
0 
0 
Amylodextrin 
(Ci 2 H 20 O 10 ) 3 
1 ^ 
OS 
— 
O 
0 
O 
0 
0 
Lactose 
342 
— 
O 
0 
O 
0 
0 
Glycerine 
C 3 H 5 (OH) 3 
9 2 
0 
O 
0 
O 
0 
0 
Ethyl alcohol 
c 2 h 6 0 
4 6 
0 
O 
0 
O 
0 
0 
Asparagin 
C 4 H 4 0 3 (NH 2 ) 2 
132 
— 
O 
0 
O 
0 
0 
Urea 
CO(NH 2 ) 2 
60 
N? 
O 
0 
O 
0 
0 
Malic acid 
QH 6 o 5 
134 
R 
R 
R 
A 
a 
0 
Maleic acid 
QHA 
116 
R 
R 
R 
a 
0 
0 
Tartaric acid 
c 4 h 6 q 6 
150 
— 
— 
0? 
0 
0 
0 
Citric acid 
c 6 h 8 o 7 
192 
— 
— 
0? 
0 
0 
0 
Oxalic acid 
c 2 h 2 o 4 
90 
— 
— 
0? 
0 
0 
0 
Magnesium sulphate 
MgS 0 4 
120 
N 
A 
a 
0 
0 
0 
or at a concentration isomolecular with one less than yfJto 
mol potassium nitrate. A rough estimate gives us, therefore, 
the result that malic acid attracts at least fifty times more 
strongly than potassium nitrate. 
For the other salts which attract the concentrations neces¬ 
sary to cause a just appreciable attraction have not been 
precisely determined. They are, however, near those iso¬ 
molecular with - r J-Q mol potassium nitrate, in some cases 
slightly higher, in most slightly lower. It would seem, 
Pp 
