134 ARTIFICIAL PARTHENOGENESIS AND FERTILIZATION 
The first vertical column of Table XVIII gives the length of 
time that the eggs had remained in the acid, and the other 
vertical columns give the percentage of the eggs which farmed 
membranes after this exposure to the different acids. 
TABLE XVIII 
Length of Exposure to | Formic | Acetic lauie Butyric |Caprylic | Nonylic 
N/1,000 Acid Acid Acid Acid Acid Acid 
PoMIMUtek seeeee ee ae 0 0) 0 0 10% | 100% 
LSsminutesss 2 sees 0 0 0 5% SO |e eae 
2uMIMUbeSsy seas 0 0 5% 10:2) 00S )\hee eee 
ZeaMINUtess ciseae eee 0 +% 40 +}. eel eee 
Ss minutes ee 0 5 50 90)... Sl are 
Sy AMIMUtES 4. ete e 13%| 60 95. +| Se sieeeeree 
ASTMINUEES esse ole icca stores 30 ns 75 LOO Se Seo eee 
As MINUGeS!., cs cis coe 90 Seas ve Mere ees oe 
SUMINUGES). -acisacieseoe 100 Se sede eacate cerca | nae Nee eee 
It will be seen that the greater the number of carbon atoms 
in the acid molecule the shorter is the time which is necessary 
to cause membrane formation in a definite percentage of eggs. 
This result is intelligible on the assumption that those acids 
which diffuse most rapidly into the egg call forth membrane 
formation in the shortest time. This behavior of the acids is 
analogous to that of the alcohols whose narcotic and haemolytic 
activity increases also for the same series with increase of the 
number of carbon atoms. In the alcohols, however, the in- 
crease of activity is much quicker than that found by us for 
the acids, for each member of the series is about two or three 
times as effective as the preceding one. 
Although the question of the influence of the concentration 
of the acid upon its effect is not so intimately connected with 
our subject, one example may be noted here for the sake of 
completeness. I quote two sets of experiments, one with 
1 Wiihner and Neubauer, ‘‘Hamolyse durch Substanzen homologer Reihen,’’ 
Arch. f. exper. Path. u. Pharm., LVI, 333, 1907; Overton, Studien ueber Narkose. 
Jena, 1901. 
