ELASTIC TISSUE. 125 



uninjured), and torn it asunder a little, it was examined with 

 the microscope ; tlic first appearance presented was that of i 

 great quantity of isolated cells, floating about in the sur- 

 rounding fluid, each of which had its peculiar nucleus. (See 

 plate III, fig. 12.) This easy separation of the cells is 

 never seen in the same degree in the areolar and fibroid 

 tissues, as they are there connected together by the cytoblas- 

 tema, and by the tough fibres issuing from the cells. These 

 cells of the coat of the aorta vary very much in shape. See 

 the figure.) Some are round, but most of them oblong, some 

 terminate with a blunt extremity, others are acuminated on 



a/ ' 



two or more sides, others again are prolonged into small pro- 

 cesses/ which again subdivide, but never extend to any great 

 length. Many of them are somewhat compressed laterally. 

 They all have a granulous aspect, but that appearance, so far 

 as one can judge by roiling the cells about, seems to be refer- 

 rible to the cell-membrane, and the contents appear to be 

 transparent. The nucleus, enclosing one or two nucleoli, 

 is attached to the interior of their walls. It is sometimes 

 round, at others more or less elongated. These cells have 

 become disengaged from the small portion of the coat of 

 the artery before described. When the preparation itself is 

 examined, many more cells are observed in it, and in addition 

 to them, distinct elastic tissue, consisting of a network of 

 minute, elastic, rough (?) (rauher) fibres, such as are found 

 nearest to the internal coat of the aorta in the adult. (See 

 Eulenburg, de Tela elastica, fig. 9.) It dees not, however, 

 present any fibres so thick as those which are found in the 

 external layers of the same part. A blighted nucleus may 

 be recognized here and there in the network. What relation, 

 then, do these cells bear to this still delicate, but so far as 

 regards its characteristic features, perfectly-formed elastic 

 tissue ? Analogy would lead us to suppose them to be 

 the primitive formation ; I sometimes also thought, that in 

 rare instances I could observe an immediate transition ; that 

 I could see, for instance, one of these cells, furnished with a 

 nucleus, pass continuously on one side into a small portion of 

 reticular tissue, resembling in appearance the undoubted clastic 

 tissue, whilst on its other side it retained its perfect cellular 

 figure. But this occurred so rarely, that I am not enabled to 



