210 SUMMARY OF CURRENT RESEARCHES RELATING TO 



wliich are produced by the strain on the tenacious outer layer acting 

 in one direction, occur here also (Figs. 5, 6, and 7). Along them we 

 see the granules hasteuiug forward in several sti'eams, whilst a clear 

 mass of protoplasm, free from granules, in constant flow, moves on 

 before them. A remarkable -circumstance is that on the leading part 

 of the body, pseudopodia with their cones frequently persist, and thus 

 to a certain extent may act as extended feelers (Fig. 7). 



While at the end opposite to that which is pushing forward the 

 double contour is distinctly preserved in the outer layer, it disappears 

 entirely on the anterior part (Fig. 6), from which it seems that the first 

 mentioned part of the body retains its toughness, v/hilst anteriorly 

 all becomes in flux, i. e. the more fluid constituents collect there. 

 Nevertheless, even these still have considerable density, as is proved 

 by the pseudopodia and pseudopodial cones protruded from them, 

 on which, however, no double contour is visible. Frequently a zone 

 of clear protoplasm seems to surround the whole body, and tben the 

 double lines are no longer seen anywhere. 



EXPLANATION OF PLATE III. 



Fig. 1. — An Amreha tentaculata with many pseudopodia. 



Fig. 2.— Another. 0"12 mm. long, under a high<-r power (Hartnack eye-piece 

 3, objective 10 immersion). It shows the cortical zone (/• s), the pseudopodia 

 (p s) on their cont s, and at A a cone of which the pseudopodium has been retracted 

 (crater). 



Fig. 3. — A portion with three pseudopodia highly magnified. 



Fig. 4.— a specimen with a number of craters (A). 



Fig. 5. — A specimen in wliich the cortical zone is dissolved. 



Fig. 6. — A flowing A. tentaculata, in which the nucleus (?») is very distinctly 

 visible. 



Fig. 7. — Another, in which three pseudopodia {j) s) are still retained on the 

 advancing part. 



Fig. 8a. — A pseudopodium with its cone, m, the soft interior mass; r, the 

 cortex ; ]?, the [pseudopodium. 



Fig. 8b. — A pseudopodium in course of being retracted. 



Fig. 9. — An A. actinophora, with a distinct cortic:il layer (r s) and a tuft of 

 pseudopodia at one end (Hartnack eye-piece 3, objective 7). 



Fig. 10. — Another, with few pseudojaodia, distinctly showing how they break 

 through the cortex. (Rather too large in proportion to the foUowing figures.) 



Fig. 11. — The same example a short time afterwards. The cortex (r s) is 

 almost everywhere li(]uefied, and has become converted into a clear space (Ji) ; 

 n, tlie nucleus whicli is distinctly visible in this state. 



Fig. 12. — The same, with the cortex comi)letely dissolved ; v c, contractile 

 vacuoles. 



Fig. 13. — The same, in slow flow in tiie direction indicated by the arrows; 

 r s, the newly reconstituted cortex. 



Fig. 14. — Another example, in which the cortex has just become liquefied, 

 but it is still retained at one spot together with two pseudopodia. 



Fig. 15. — An Amceba, in which the cortex has dissolved before two pseudo- 

 podia (2^ s) were retracted. Tliese became liquefied soon afterwards. In this 

 and 



Fig. 16 tlie granular protoplasm is sharply separated from the hyaline 

 zone. This, however, only lasts for a few moments to give place to the state 

 in Fig. 12. 



Fig. 17. — An Amaiha, in which the liquefaction of the cortex has just com- 

 menced on one side, treated with osmic acid. The cortex (r s) appears finely 

 punctuate, as also the hyaline sarcode ; the nucleus at ?i. 



