367 



point, is inserted, from which the water drops constantly. The frequency of 

 the drops, i.e., the velocity of the current throu£;h the whole system, is regu- 

 lated by varying the height of the dropper, for which purpose it is 

 attached to a movable support (A'), which slides up and down i; ;; 



on a vertical stem inserted in the stage of the microscope, and ■ i ■ ; 

 may be fixed at any position by a screw. Heuce, the tempera- . r — j ; 

 ture of the water which is supplied to the warm stage {A) -A \\ 

 being constant, and the loss of temperature by radiation and ;:'! , f:i 

 otherwise being also tolerably constant, the arrangement just 

 described affords to the observer a means of so adjusting the 

 flow from T that the temperature of A is also constant. 



All that remains is to describe the means by which evapora- 

 tion from the surface of the saline solution, contained in the 

 bath in which the mesentery is laid, is compensated. For this 

 purpose the hot-water tube gives off, at D. a branch which 

 immediately terminates in a capillary end. From this end hot ;; 

 water drops constantly, at a rate which must be regulated at I; j; 

 the beginning of the observation, once for all, by means of a \\ j; 

 constricting screw at D, which for want of room is not shown in 

 tlie drawing. 



Before beginning observations, the bath, B, must be placed on the warm 

 stage charged with saline solution, and allowed to remain there until it has 

 acquired a constant temperature. The rate of flow must then be adjusted 

 by varying the height of the dropper until the reading of the thermometer 

 in the bath is about 37° C. 



On the Cellular Elements 0/ Tendons a«c?o/ Loose 

 Connective Tissue. By Dr. L, Ranvier.^ 



With Plate XX. 



I PURPOSE ill this paper to describe the forms and relations 

 of the elementary cells of tendons and of ordinary connective 

 tissue. The results Avhich I have obtained by new means 

 of analysis differ in many respects from those which now-a- 

 days are generally believed and taught on the subject of 

 connective tissue. They considerably modify the manner of 

 investigating this tissue, as much as to its physiological as to 

 its pathological condition, and render the interpretation of 

 certain facts much clearer. 



I. It seems to me necessary, first of all, to sketch broadly 

 the history of the fluctuations of histology on the subject of 

 the cells of connective tissue. It is necessary, in fact, that 

 readers should be acquainted with the discussions on this 

 subject, and know how to appreciate the state of our know- 

 ledge on connective tissue, which, from a pathologist's point 

 of view, is the most important tissue of the whole organism. 



^ Translated from the ' Archives de Phvsiologie,' tome 2. 



