. The biology of Stentor. Stentor. ANALYSIS OF STENTOR 243 common fixing agents. From this fact together with the general similarity between the response of stentors and nerve preparations to the drugs and antagonists which he tested, Neresheimer con- cluded that the effects were not on the myonemes themselves but on the " neurophanes " which were therefore of a neuroid character. Dierks was, of course, of the same opinion with regard to his '' neuroids " and he found that coeruleus became insensitive to touch in KCl, while CaCL increased contraction and was antagonistic to the
. The biology of Stentor. Stentor. ANALYSIS OF STENTOR 243 common fixing agents. From this fact together with the general similarity between the response of stentors and nerve preparations to the drugs and antagonists which he tested, Neresheimer con- cluded that the effects were not on the myonemes themselves but on the " neurophanes " which were therefore of a neuroid character. Dierks was, of course, of the same opinion with regard to his '' neuroids " and he found that coeruleus became insensitive to touch in KCl, while CaCL increased contraction and was antagonistic to the action of potassium; for animals made insensi- tive in the potassium salt regained their irritability when calcium chloride was added. Relaxed stentors still contracted when fixed with Flemming's solution. But contraction of the cell in strongly coagulating solutions can scarcely be taken as demonstrating that the myonemes were not directly affected and the impression remains that much more sophisticated studies will be needed to demonstrate similarities and differences between the responses of stentors and typical nerve-muscle preparations. Merton (1932, 1935) also attempted to treat stentors so that they could be fixed and stained in the extended form. Anticipating Dierks, he found that KCl gives a partial anaesthesia of the myonemes. In dilute Ringer's solution, stentors became out- stretched but their irritability was increased. Metal salts of iron and copper were said to produce differential contractions of the cell and from his description it appears that the anterior end of the stentor contracted while the tail-pole remained extended. Copper sulphate produced a hardening of the cortex which therefore antagonized the contraction of the myonemes and left stentors in a semi-extended state. Fairly well extended preparations were made by relaxing stentors for 2 to 3 hours in Ringer's solution diluted 1:3, then applying weak copper acetate to harden the surface, following this
Size: 1508px × 1657px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
