REVIEW. 279 



In the second chapter are discussed the celhilar elements 

 of the ground-substance or connective-tissue-covpuscles. 

 These are described as flat branched cells lying parallel to 

 the surface, and, as shown by Rollett, in the cornea, the lymph 

 canalicular system corresponds to these cells. Spherical or 

 lymphoid cells, of which all intermediate sizes exist, from a 

 rounded nucleus with a thin zone of protoplasm up to those 

 which are twice as large as a common colourless blood- 

 corpuscle are seen in the lymph canalicular system. The 

 origin of fatty tissue is illustrated partly by a description of 

 a gelatinous body which lies in the infra-orbital fossa of 

 young rabbits, and which is composed of rudimentary adipose 

 tissue or raucous tissue. 



It is not easy to give a condensed account of Dr. Klein's 

 observations on the lymphatic vessels of the serous mem- 

 branes, which form the subject of the third chapter. The 

 essential points have, however, been already stated in this 

 journal, in the article before referred to. 



With regard to blood-vessels, Dr. Klein holds that new 

 capillaries are formed from those previously existing both by 

 the continuous excavation of the branched cells connected 

 with their walls, and are also formed in an isolated manner 

 in the branched cells themselves, becoming united ultimately 

 with the existing capillaries. This method is similar to that first 

 pointed out by Strieker in the new formation of blood-vessels 

 in the tadpole and in inflammation, which was afterwards 

 confirmed by Arnold. 



We cannot here enter upon the pathological relations, but 

 they illustrate in a surprising manner the normal anatomy of 

 the parts, and supply fresh example, if any were needed, of 

 the close connection of physiology with pathology. 



We may also point out that many of these observations 

 have more than a professional or pathological interest. The 

 morbid changes of the cell-elements, which he describes and 

 figures in great detail, are of the highest importance for the 

 general question of the vital phenomena of protoplasm. 

 Moreover, the full account, such as we now have, of the 

 histology of the serous membranes of the peritoneal cavity, 

 cannot but excite the attention of the comparative anato- 

 mist, who will not fail to recognise in many of the structures 

 and processes of growth described the counterpart of pheno- 



communicated to the Medical Microscopical Society in June of last year. 

 See this Journal for 1873, p. 309 ; also ' British Medical Journal,' March 

 2l8t, 1874. 



