320 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Now tills may be very well theoretically, but are these three 

 factors equal to the occasion ? is the question before us. I have imitated 

 the structure of the Amoeba in the following way: — 



An indiarubber ball is pierced by two or three holes near together ; 

 these should be about the diameter of a common darning-needle. A 

 larger aperture (half an inch across) is then made in the ball, but 

 opposite to the smaller holes, and the ball half filled with white 

 of egg (unboiled) tinted with magenta. The ball represents the 

 stroma, while white of egg takes the place of the interstromal 

 matter. The ball is now dipped into a beaker of water to which 

 Bugar has been previously added until its specific gravity is equal to 

 that of white of egg. Place a finger over the aperture through which 

 the ball was filled, and press upon it with the other fingers of the 

 same hand. Beautiful little magenta-stained pseudopodia will be 

 projected from the small apertures into the sugar solution, and on 

 relaxing the pressure, still keeping the finger over the aperture above, 

 the pseudopodia will be completely retracted. I have been able in 

 this way to project them three or four inches, and afterwards they 

 have been completely retracted. 



One might use common water in place of sugar solution, but as 

 the specific gravity of the white of egg is greater than that of the 

 water, the pseudopodia, when they have been projected more than an 

 inch or so, break off and fall to the bottom. The size of the aperture 

 is also rather a nice point, for there is one size — roughly ^^ inch in 

 diameter — which is best suited for white of egg, although any sized 

 aperture will answer, though not so well. This no doubt varies with 

 the fluid used ; ordinary ink may be substituted for white of egg, and 

 oil for the sugar solution." 



The author cannot but believe that in the stroma the active cause 

 for these movements is to be sought for, and, as far as he can see, 

 the mode described above for its action is least in antagonism to 

 known facts. 



While, no doubt, many of the bulgings seen in the white corpuscle 

 of the newt's blood are due to changes in shape of the whole cell, 

 probably with slight local accumulation of interstromal matter, yet 

 may it not be that many of those fine hyaline processes are but inter- 

 stromal matter projected from the cell ? 



Distinctions between Organisms and Minerals.* — In 1878 G. 

 Fournier, by mixing together certain inorganic salts, produced pseudo- 

 organisms, which in form and structure might easily have been con- 

 founded with cryptogamic plants, and similar experiments have now 

 been made by D. Monnier and C. Vogt, who describe them as 

 follows : — 



Figured elements presenting all the cliaracteristics of form 

 belonging to organic elements, such as cells, simple and with 

 porous canals, tubes with sides, with septa, and with heterogeneous 

 granular contents, may be produced artificially in an a2:)propriate 

 liquid by the joint action of two salts forming by double decom- 



* Comptes Rcndup, x^-iv. (1882) pp. 45-6. 



