276 Dr L. Mandl's Besearches on the 



anastomose with each other^ or are continued without interruption ; these 

 arc the cellular lines, for they have their origin in the cells. Finally, a 

 kind of spines exists on a great number of scales, on one of their edges, 

 which we call the teeth of the scales, a denomination founded on the 

 development of these bodies. 



Around the longitudinal and transverse lines, principally towards the 

 points where the longitudinal lines converge, viz. the focus, we find some 

 yellowish corpuscles, more or less elUptical, which we name the corpuscles 

 of the scales ; and lastly, upon tearing awa}- or raising the upper layer 

 of the scale, an inferior fibrous layer makes its appearance. 



Each of these formations will be specially treated of; but, in order to 

 facilitate description, it will be advisable to divide the scales into several 

 parts. Let us suppose lines drawn from the four corners of the scale, as 

 we have already seen more or less marked in nature — (pi. III. fig. 2) — 

 across the point of convergence of the longitudinal lines ; the scale will 

 then be divided into four quarters or fields. We name (and have drawn 

 the scales conformably to these denominations) that portion which is im- 

 planted in the skin, and directed towards the head, the hasal field ; that 

 opposite to it, directed towards the tail, and which, from its imbricated 

 position, is free, and not covered by the other scales, the terminal field. 

 Asa consequence of these denominations, the right field lies next the dorsal 

 region, and the left field towards the ventral region. These two last are 

 almost always identical, and we name them the lateral fields. 



The scales of carj), and of some other fishes, distinctly present this di- 

 vision into four parts; and it is easy to recognise the regions indicated in 

 every scale. 



Longitudinal Canals. — The longitudinal lines which run from a com- 

 mon point, the focus of the scale, towards the periphery, are of great im- 

 portance in the anatomy of the tissue we are now examining. Hitherto 

 no opinion has been expressed regarding them, because at first they were 

 not examined, and subsequently because authors, perceiving in the cellu- 

 lar lines the limits of continual increase, hastily passed over in silence an 

 appearance which they could not explain, and which likewise threatened 

 to be strongly opposed to the views they were advocating. 



If it so be that the scale, as was first stated by Leuwenhoek, and as 

 all authors have repeated up to the present time, is composed only of su- 

 perimposed layers s-milar to each other, aud whose edges are marked by 

 these more or less concentric lines which we call the cellular lines, how 

 are we to explain those broad strise which issue from a common centre, 

 and which, by interrupting the peripheral lines, often separate the latter 

 bj- wide and vacant spaces .'' How comes it to pass that such broad 

 bands, amounting to ten, twenty, or even more, exist in a scale, and are 

 not marked by the lines which denote the continual growth of it ? 



Authors have thus been in general contented by calling these lines fur- 

 rows, diverging in the form of a fan, &c. By the examination to which 

 we have subjected them, we have succeeded not only in determining the 



