ON THE LAMINAR TISSUE OF AMPHIOXUS. 
421 
On the Laminar Tissue of Amphioxus. By Professor 
PoucHET. (With Plate XXIX.) 
The chief results in this paper were communicated to the 
Societe de Biologic at their meeting on May 1st, 1880.^ 
I. I was lately fortunate in obtaining large numbers of Am- 
phioxus at Concarneau, and I used them in endeavouring to 
clear up a special point in their histology, which seems to have 
been only very imperfectly touched upon by the numerous 
authors who have studied this animal. I intend to speak 
of the system of canals and cavities, which from a point of 
view, which is perfectly legitimate, are comparable to fin 
rays. Both of these systems are differentiations of what 
may be termed *naminar tissue.” 
In 1849 M. de Quatrefages applied the term “ singular ” to 
the laminar tissue of Amphioxus. Since that time the system 
of spaces and canals which have been observed have not been 
the object of special study. The fact has been recognised 
that they do not communicate with the blood capillaries, 
but their histological structure has remained obscure, 
M. Reichert is the only author who has touched upon it, and 
he seems to have guessed at, rather than proved, their analogy 
with the constant elements of the laminar tissue. He ex- 
presses himself thus, ^^Da das bindegewebige Stroma uns als 
pellucide Grundsubstanz angesehen werden Kami und die 
dazu gehorigen Bindesubstanzkorper fehlen, so ware es 
moglich dass das in Rede stehende netzformige Gebilde 
den zellenhalftigen Theil des bindegewebigen Stromas dars- 
tellt, unter dessen Vermittelung die in grosser Menge ver- 
breitete, ganz hyaline Grundsubstanz gebildet werde.”^ 
In 1873 Stieda^ contents himself with quoting these words 
of Reichert, which in fact contain the true state of the case. 
Before Reichert’s papei\ was published, Owsjannikow^ de- 
scribed, in 1868, in the region of the tactile corpuscles, that 
is to say, round the mouth, connective-tissue cells, gross, 
liinglich, zuweilen sternfbrmig,” and compared them to the 
cells of the cornea, an error of observation as will be seen 
further on. 
» ‘See ‘Gazette Medicale’ for May 22, 1880. 
2 Reichert, ‘ Arch. f. Anat.,’ 1870. 
^ “ Studien iiber den Amy)hioxus lanccolatus,” ‘ Mem. dc 1’ Academic 
de SL Petersberg,’ viie Serie, Tome xix, No. 7, 1873. 
^ “ Ueber das centrale Nervensystem des Amphioxus lanccolatus,” in 
Bullet, de I’Acad. de St. Petersbourg,’ T. xii, 18G8, p. 290. 
