116 Irving Hardesty 



Henle, the former of whom discovered it independently and gave it the 

 name, membrana iectoria. Embryological investigations of the struc- 

 tures found in the cochlea began almost simultaneously with the purely 

 anatomical. As early as 1854 Eeissner described in embryos the sepa- 

 rate existence of the ductus coclilearis, discovering its limiting spiral 

 lamella, afterwards called Eeissner's membrane by Kolliker and mem- 

 hrana vestibularis by Henle. However, it was Kolliker who, in 1861, 

 first described the formation of the ductus coclilearis from the ecto- 

 dermal tube and suggested the process by which Corti's organ is 

 elaborated and also the normal position and morphological signifieance 

 of the tectorial membrane. 



None of these earlier papers and but few of those following indicate 

 satisfactory or complete observations as to either the consistency, bulk, 

 extent, shape or actual structure of the tectorial membrane. Most of 

 them saw in their preparations little more than an amorphous mass of 

 very varying shape and very varying relation to the cells of the organ 

 of Corti. Henle, in volume 2 of his Handbuch (1866), believed the 

 membrane to be very delicate, yet firm and resistant, and of an especial 

 elasticity; Bottcher, '69, also concluded that it possesses a high degree 

 of elasticity; Nuel, '75, cited by Eetzius, denied elasticity, but claimed 

 for it a soft gelatinous nature; Gottstein, '73, considered it strongly 

 elastic, and Lavdowsky, '77, considered it a soft, elastic mass, fragile 

 and distensible and in large part homogeneous. Eetzius, '84, examined 

 it in aqueous humor and pronounced it transparent, soft, gelatinous, 

 tolerably elastic, capable of some stretching, but that it would split 

 under increased stress in the direction of evident fine fibers present in it, 

 and found it more firm after the action of fixing fluids; Dupuis, '94, 

 considered it not of a mucous consistency, but decidedly elastic; A^an 

 Ebner, '02, describes it as a fragile, easily distorted, fibrous structure. 

 Kishi, '07, who examined it in salt solution as well as in the fixed 

 condition, found it to possess a marked elastic character and to shrink 

 when subjected to the ordinary procedures; Avhile Shambaugh, '07, in a 

 theoretical paper, considered it a lamellar structure of the same specific 

 gravity as the endolymph in which it lies. 



It will be noted that a majority of the authors cited above agree on 

 one point, namely, that the tectorial membrane possesses elasticity. In 

 mv trials to obtain intact specimens of the membrane in the fresh 

 condition, several physical characters seemed uianifest. In the first 

 place, even in proportion to its size, it is, in the fresh, most incon- 



