220 REMARKS UPON A STATEMENT 



a nucleus, aud around this again a cell. The accordance in the 

 mode of development of two so different elementary particles, 

 first led to the deduction of the principle of a similar mode of 

 formation for all elementary particles, and then to its proof by 

 observation. Therefore, what we have to decide is, first, 

 whether the idea of comparing an animal elementary structure 

 with a vegetable cell, with reference to a similar mode of de- 

 velopment, does occur in Valentin's earlier observations ; and, 

 secondly, whether Valentin has recognised the principle which 

 is contained in the similar mode of development of two ele- 

 mentary particles which, in a physiological sense, are very dis- 

 similar. In my preface I have given a brief historical sketch 

 of the subject from my own point of view, and Valentin's 

 remarks do not convince me of the necessity of making any 

 alteration in it. Impartiality, however, requires that Valentin's 

 representation should follow this statement, and I therefore 

 append the passages cited by him, word for word, from his 

 works : 



" In my first Mstogenetic researches, I observed certain pecu- 

 liar granules lying in a transparent gelatinous substance, as the 

 primordial matter of all the tissues. I pointed out the difference 

 between these granules in the serous and mucous layers, at the 

 period of the earliest separation of the layers from one another, 

 hi the vascular layer I found large globules or cells, which, in 

 respect to their form and juxtaposition, I compared, as early as 

 the year 1835, with vegetable cellular tissue. (Entwickelimgs- 

 geschichte, 287. The vascular layer seems to be composed of large 

 globules having a mean diameter of 0*001013 Paris inch, which are 

 perfectly transparent in their interior, and so closely crowded toge- 

 ther, that they are flattened against one another at many of their points of 

 contact, and assume an hexagonal form like the cellular tissue of plants.) 

 / also first directed attention to the resemblance in form of the 

 cartilages in which ossification was commencing, and particularly 

 {from observations made in conjunction with Purkinje) of the 

 branchial cartilage of the tadpole to the vegetable cellular tissue. 

 (lb. 209-10. The cartilages of the labyrinth present a variety of form 

 whilst passing through the process of ossification, which differs very 

 essentially from most of the other cartilages of the body, which will be 

 described at greater length presently. In place of the ordinary car- 

 tilage-corpuscle, they contain large bodies which are not so well defined 

 in form, most of them furnished with linear boundaries, being roundish, 



