1398] NOTES AND COMMENTS 79 
SYNTHETIC PROTOPLASM 
Proressor HERRERA also sent us a letter containing an account of 
some experiments he has made on what he calls a ‘synthetic proto- 
plasm’ made by him by mixing pepsine, peptone, acetic fibrine, oleic 
acid, soap, sugar, extract of bile, carbonate of soda, lime, and of 
ammonia, lactate of lime, phosphates of lime and magnesium, sulphates 
of lime and iron, and chloride of sodium. When this compound is 
placed in water and examined under the microscope, violent diffusion 
currents are set up, and streaming movements of a very active kind 
last for a few minutes. When this is over, the addition of a trace 
of liquid ammonia renews the activity, which lasts for several hours. 
These movements he rightly attributes to the liberation of gases by 
the particles of the compound, and he compares with this the 
liberation of carbonic oxide by living protoplasm, suggesting that in 
the discharge of that gas lies the secret of the streaming movements 
of protoplasm. Professor. Herrera was good enough to send us a 
small quantity of his compound, and on this we have successfully 
repeated some of the experiments he describes. The little mass was 
particularly active in water with a trace of ammonia: diffusion 
currents, movements of the whole mass, and the protrusion of 
pseudopodia-like processes occurred. We found, however, that the 
resemblance to protoplasm was destroyed from the fact that the 
mass did not retain its coherence; small masses were constantly 
discharged from its surface, and it seemed to melt away in a com- 
paratively short time. In this respect it compared unfavourably 
with Biitschli’s foams, and we imagine that, although Dr Herrera 
has imitated with considerable success the very complicated chemical 
composition and consequent instability of protoplasm, he has not 
been so successful with its structure. On the other hand, it is 
possible that the substance, in its postal journey from Mexico, 
has deteriorated. We think that he has begun a most ingenious line 
of experiment, and wish him all success in his further attempts. 
THE PHYTO-PLANKTON OF THE ATLANTIC 
On May 12, Mr George Murray and Mr V. H. Blackman presented 
to the Royal Society their observations on a year’s work in collect- 
ing phyto-plankton along a track from the Channel to Panama, 
carried out by Captains Milner and Rudge, and also during one 
voyage to Brazil by Captain Tindall. They also gave the results 
of their own observations on living material at sea. The material 
was obtained by the pumping method described in our June number 
(vol. xii:, p. 367). 
One of the objects of the authors’ work was to determine, if 
possible, the nature of the microscopic and little understood objects 
known as coccospheres and rhabdospheres. In the present paper 
