1892.] Effect of Movement upon Growth of Lower Organisms. 11 
second, that with the germs forming torula-like cells but little 
difference in size and shape can be produced. What difference 
there is seems to be caused not so much by the agitation of 
the fluid as by the exposure of the cells more freely to the in- 
fluence of the atmosphere. When submerged the cells grow © 
slender, with homogeneous contents, while the surface-grown 
forms were highly vacuolated and more broadly oval. The 
cells from the shaken flask agree in all essentials with those 
grown at the surface of the still flask, except that they aver- 
aged somewhat larger i in size. 
The second series of experiments bears upon the influence 
of mechanical movement upon the increase of cells. Horvath? 
“conducted a series of experiments upon bacteria and their re- 
lation to movement, in which he found that mechanical move- 
ment interfered materially with the growth of the germs. 
From this he made the sweeping generalization that move- 
ment had a retarding influence on the growth of all lower 
organisms. Hansen? investigated the subject in connection 
with his work on yeast (Saccharomyces cerevisi@) and found 
the reverse to be true. The germs increased two to set 
times faster when agitated than they did when growna 
He concluded that it was the agitation of the cell itself, aisiod 
terials, that enabled it to increase more rapidly. The in- 
troduction of air into the fluid by the apparatus he used was so 
little that he thought this point was not of much importance. * 
In the following synopsis of results, A in all cases represents 
the culture agitated and B the one that grew undisturbed. 
: NO. OF GERMS PER UNIT | PROPORTION eine 
NO. OF] KIND OF | HOURS OF OF VOLUME. . SHOWING RELA- BETWEEN 
EX) GERM. GROWTH. TIVE INCREASE IN A AND B 
NO. OF CELLS. 
BEFORE exe. | AFTEREXP, 
At Monilia 2332 1:138 ' 
Bi. candida. 94 r6.9-¢ | 1618 1: 95 145 * 
An, | Oidium |! 1262 1:270 t 
Br. | albicans. il 467+ ; 610 1 13130 ay 
Am. | Monilia 1087 1: 44 t 
: 1.41 
Bm. | candida. sak seanaill ; 767 te 31+ aut 
1 Horvath: EB jet Archiv f. d. ges. Phys XVII, £25: 
2 Hansen: fra’ Carls; Lab.,\1, 271 
3 Hansen: Hypotites de Horvath, Medd. f. Carls. Lab., 1, 96, French résumé. 
* 
