212 DR. E. KLEIN. 



modifying it in saying, that there are holes which appear at 

 first sight to be surrounded by returning bundles, but which 

 on careful examination are seen to surround only about half 

 or two thirds of the circumference of the hole. 



Staining a portion of omentum of an adult rat in carmine 

 (after having been kept a few days in the bichromate of potash 

 solution) and spreading it out with a rather firm hand on an 

 object glass and mounting and examining it under the micro- 

 scope, the arrangement of the connective-tissue bundles is very 

 evident. In some parts we see trabeculse, which are composd 

 of three bundles ; a middle one, and on each side of this a thin 

 one bordering on a hole and apparently surrounding it. But, 

 on looking more attentively, it is found that it does not return 

 in itself, but is a branch of a larger bundle, and, having sur- 

 rounded the hole for the greater part of its circumference, 

 joins again another bundle. This condition is quite com- 

 patible with the formation of the holes by vacuolation. 



3. In my 'Anatomy of the Lymphatics,' I, 1873, p. 11, 

 .nd following, I have minutely described the occurrence of 

 opaque patches of different sizes (more or less covered with 

 germinating endothelium) the matrix of which contains a 

 great abundance of cells. The youngest and smallest of 

 these milky patches have no blood-vessels, whereas the larger 

 ones are provided with a special system of capillary vessels. 

 I have also stated then (1. c, pp. 58, 59, and 60) that in tlie 

 omentum of most animals a constant development of new 

 vessels takes place in these patches of the omentum, either 

 in connection with already formed vessels by solid proto- 

 plasmic processes which become gradually hollowed out (as 

 described by Strieker and Arnold) or independent of already 

 formed vessels by vacuolation of some of the connective- 

 tissue cori)uscles of the matrix of the above-named patches 

 (the vacuolation of cells is, as I have pointed out in the 

 second section of that work, of great importance also in 

 pathological respect). 



Ranvier, a year later, in a paper published in 1874^ (1. c, 

 p. 148) , drew attention to the opaque patches in the omentum of 

 rabbit and he gave to them a special name, " laches laiteuses."" 

 Those cells of the matrix of these patches of which blood- 

 vessels are developed Ranvier calls " cellule vasoformatives."- 



' Both the reporter in the ' Centralblatt f. Med. Wissensch.,' and the 

 reporter on "Histology," in Virchow's ' Jahrbiicher,' while reviewing 

 Ranvier's paper, aro quite unaware oi' my description of the above patches 

 and their importance for the development of blood-vessels. 



"^ It seems to be necessary to have always in readiness a few new names, 

 otherwise your descriptions will be left unnoticed. 



