THEIR MICRO-CHEMICAL REACTIONS. 65 



parative demonstrations of the elements of motion in the lower 

 animals, that this contractility, or property of contracting on the 

 application of stimuli to the nerves, is not connected in the animal 

 organism solely and exclusively with the fibre-cells of the smooth 

 muscles, but appertains to other histological forms, such as amor- 

 phous membranes, tubes, vesicles, filaments, &c. 



Our interest is naturally increased, as we here find ourselves 

 dealing, for the first time, with a form of animal tissue which 

 exhibits vital activity, or, in other words, moves through the 

 influence of the nerves ; and we find, moreover, that the chemical 

 relations are here wholly different from those which we have 

 hitherto noticed in those tissues of the animal organism which act 

 solely by their physical properties. 



The following remarks embody all that is known from my own 

 observations, and those of Bonders,* Schultze,f Paulsen,{ and 

 others, in reference to the micro-chemical reactions of these 

 fibre-cells. 



The most generally known of these is the action of acetic acid, 

 which, when employed in a more or less diluted state, causes the 

 substance of the fibre to swell, whilst it increases its transparency ; 

 the nucleus, which was pale and scarcely visible, now stands out 

 more prominently, and commonly presents the appearance of a 

 sharply outlined, baton-shaped, often somewhat bent and even 

 twisted dark body, in which no nucleolus can be seen. According 

 to Kolliker, acetic acid frequently causes the nuclei to contract in 

 a slight degree ; not unfrequently, it induces an augmentation in 

 their breadth, rendering the nuclei paler instead of darker. 



Concentrated acetic acid completely dissolves the fibre, until 

 even the nuclei are gradually rendered indistinct. Fat-globules 

 and molecular granules are then the only things to be discovered 

 between the hyaline fibres of connective tissue. 



Extremely dilute hydrochloric acid (1 part of anhydrous acid 

 in 3,000 parts of water) behaves in almost the same way as 

 dilute acetic acid, although, according to my experience, in a more 

 decisive manner. The nuclei appear more distinct and dark, the 

 substance of the cell becomes very pellucid, but at the same time 

 assumes a curled or wave-like appearance ; the nuclei lying in a 

 curve of the fibre present, collectively, a crescentic appearance, 

 and their extremities are in some cases twisted in opposite direc- 



* Op. cit. 

 f Op. cit. 

 t Op. cit. 

 VOL. III. F 



