492 The American Naturalist, [May, 
MICROSCOPY. 
Professor Butschli’s Experimental Imitation of Proto- 
plasmic Movement.'—Professor Biitschli,of Heidelberg, has recently 
made some extremely interesting observations upon a substance which 
simulates in a remarkable way the appearance and movements of pro- 
toplasm of an Amoeba, or of the plasmodium of Mycotozoa. He has 
been kind enough to send to me some oil in a suitable condition for 
use, with directions as to the exact details of the experiment. In my 
laboratory, by following his directions, the movements described by 
him have been observed in a satisfactory manner, In order to obtain 
the best results some experience and care is requisite, and probably 
cannot always be obtained by a single experiment, The subject is so 
interesting, and so fitted for further investigation by all who have leis- 
ure and taste for the study of the vital phenomena of the Protozoa, and 
of living protoplasm in general, that I think it will be of advantage to 
the readers of this journal to have Professor Biitschli’s directions, which 
he has permitted me to publish, placed in their hands.—E. Ray LAN- 
KESTER. 
March, 1890. 
HEIDELBERG, February 1st, 1890. 
You have kindly asked me how I prepared the protoplasma-like drops 
which I have described. As you yourself feel greatly interested in this 
discovery, and presumably a like interest exists among other English 
biologists and microscopists, I hasten to satisfy your desire, and to - 
explain somewhat more fully the methods which I have described in a 
previous publication. 
As you well know already, I use in the preparation of these globules, 
—showing protoplasma-like streaming,—ordinary olive oil. My first 
experiments were made with a small quantity of olive oil, which had 
been standing for a long time in my laboratory in a small bottle. 
By some happy chance this oil had just the right properties which are 
necessary for the success of the experiment, for not every sort of oil is 
suitable. As far as my experience goes it tends to show that the 
ordinary oil cannot be directly used, because it is too thin, or is per- 
haps deficient in other qualities on which the success of the experiment 
depends. In order, therefore, to prepare a suitable oil, I proceed in 
the following manner: A medium-sized watch-glass, or flat dish, is 
1From the Quarterly Journal of Microscopical Science, Vol. XXXI. April, 1899. 
