258 DR. G. THIN. 



to associate the transverse markings with the existence of 

 this network without attempting to explain the connection 

 between them more definitely. 



The spindle elements had also completely disappeared. 



As bearing on this matter I may remark that in the mus- 

 cular fibre of a mouse which had been treated by chloride of 

 gold solution and then sealed on an object -glass in diluted acetic 

 acid, I found the following change after the preparation had 

 been laid aside for more than twelve months. On one part 

 of the fibre the transverse markings had persisted, and were 

 more than usually well marked, the fibre at that part having 

 an appearance as if it were bound with hoops, each transverse 

 marking resembling one hoop. As far as the hoop-like 

 arrangement persisted the fibre was small and of uniform 

 calibre. At the other end there were no transverse mark- 

 ings, the fibre was fibrillated, and from a third to a half 

 broader than where the transverse markings had remained. 

 The last of these markings consisted of a distinct ring that 

 seemed to pass round the fibre, and immediately beyond it the 

 fibres spread out as if freed from a constriction. (The appear- 

 ance so produced may be familiarly illustrated by likening it 

 to that of a birch broom). In this fibre the connection of 

 the transverse markings with a binding together of its con- 

 stituent parts is unmistakable. 



In the paper published in the ' Proceedings of the Royal 

 Society,' No. 155, 1874, I described and figured appear- 

 ances produced in muscular fibre by saturated solution of 

 caustic potash, according to the method afterwards more 

 minutely described in the January number of this Journal. 

 In frog muscle which had been subjected to the solution at a 

 temperature of 107° Fahr., the solution being allowed to 

 cool, I have lately several times observed fibres in which the 

 primary bundles were as clearly defined as in the prepara- 

 tions figured in the plate which accompanies this paper, and 

 I have also several times seen the fibrilla in such prepara 

 tions perfectly isolated. Success in these respects is in 

 potash preparations exceptional, and was accidentally ob- 

 tained by observing fibres which had adhered to other 

 tissues on which I was operating. 



A few words regarding the logwood solution may not be out 

 of place. It is different from the solution prepared from crys- 

 tallized hgematoxylin according to the formula of Bohm. Dr. 

 Klein gives a formula for its preparation at p. 378, vol. xiii 

 (new series) of this Journal, which he states is similar to a 

 method prescribed by Professor Arnold. I have not suc- 

 ceeded in verifying the reference to Professor Arnold's paper. 



