392 THE CORNEA, BY ALEXANDER ROLLETT. 



At a time when the cells present in the cornea received but little 

 consideration, though extensive use of the microscope was made, and 

 with very valuable results, for the investigation of animal tissues, the 

 substance of the cornea propria was regarded as a tissue composed 

 simply of fasciculi of fibres.* At a still more remote period a lami- 

 nated structure was attributed to the cornea, so that according to 

 Haller it is composed of many laminae. 



These laminae corneae of the older anatomists have again appeared 

 in the foreground, owing to Todd and Bowmanf having described the 

 cornea propria as a " laminated membrane," and recognized the 

 presence of more than sixty lamellae in the human cornea. 



Todd and Bowman, however, described their corneal lamellae as 

 consisting .of a peculiar modification of the white fibrous tissue 

 (fibrillar connective tissue) of the sclerotic, with which the lamellae are 

 directly continuous. The several lamella are further, according to 

 them, so intimately connected with each other by numerous bridges 

 of the same material, that it is impossible to follow any individual 

 lamella beyond a small distance. If now we reflect over this de- 

 scription, the question immediately arises whether the term "laminated 

 membrane" applied to such a structure as that described by Bowman 

 is well applied. Bowman]: subsequently described the fibrous tissue 

 in a similar manner. Although we find Bowman cited in evidence of 

 the microscopic proof of a lamellated structure of the cornea, and the 

 lamellae of Bowman are spoken of, the account to which this term 

 may be fairly applied was first given by Henle in 1852, in opposition 

 to his earlier views. Thus, according to him, the matter of the cornea 

 is formed by " homogeneous lamellae," the number of which however 

 (about 300) far exceeds the estimate of Todd and Bowman, but which 

 all run parallel to the surfaces of the corneae. A further development 

 of the views at that time entertained by Henle will be found in 

 Dornbluth. II 



* Valentin, Repertorium der Physiologic, 1836, p. 311; Donne, A. Insti- 

 tut, 1837, No. 220 ; Henle, Allgemeine Anatomie, p. 320 (Leipzig, 1841) ; 

 Pappenheim, Specielle Gewebelehre des Auges, p. 55 (Breslau, 1842) ; 

 Briicke, loc. cit. , p. 9, and others. 



t The Physiological Anatomy and Physiology of Man, p. 17. London, 

 1845 and 1847. 



+ Lectures on the parts concerned in operations on the Eye, p. 10. 



Canstatt's Jahresbericht fur 1852, Band i., pp. 26 and 27. 



|| Henle and Pfeuffer, Zeitschrift fur rationelle Medicin, N.F. } Bande 

 vii., p. 212, and viii., p. 156. 



