260 ^- W. SPENGEL, 



I 



verse sections remains to be obtained by future inquiry." Für die 

 Deutung der übrigen Canäle als Blutgefässe weiss Lankester aus- 

 schliesslich anzuführen, dass sie ihm wahrscheinlich dünke. „The 

 bloodvessels which are given off right and left from the great artery 

 of the endostyle pass into tke bases of the primary bars, where their 

 rods bifurcate" [wie seit Joh. Müller bekannt ist], „and are pos- 

 sibly and probably continned up the primary bars in the channel 

 marked Bl. vess. in fig. 1. It is, however, to be noted that this 

 channel is very narrow relatively to the vessels given off from the 

 median ventral artery of the endostyle, and that the tongue-bars cer- 

 tainly receive no such branches from the eudostylar artery, although 

 the channel exists in them also." Lankester fährt dann fort: 

 Schneider figures a vessel passing from the dorsal end of each bar 

 — both tongue bars and primary bars — into the dorsal aorta; and 

 possibly a communication exists between the vessel of each primary 

 bar and that of the adjacent tongue bars by means of the transverse 

 junctions which occur at intervals along the length of the bars. I h a v e 

 not been able to satisfy my self as to the existence of 

 the communications with the dorsal aorta described 

 by Schneider" [und lange vor diesem durch Joh. Müller^), 1. c. 

 p. 106, tab. 5, fig. 6], nor as to the existence of vessels 

 in the transverse junctions. At the same time it is seems 

 vefy probable that both exist" (p. 384). 



Im Ganzen erscheint Lankester das Gefässystcm des Amphioxus 

 als degenerirt (p. 379), und er bemerkt darüber: „It can scarcely be 

 maintained that the disposition of the blood-vessels in Amphioxus lends 

 itself to the conclusion that we have here a highly efficient branchial 



respiratory apparatus. The probably degenerate condition of the 



vascular system in Amphioxus has led me to doubt whether the 

 spaces marked Bl. vess. in figs. 1 and 2, pi. 36 B, are really con- 

 tinued as distinct vessels to the dorsal aortae; it is not unlikely that 

 such a continuation exists, but it is also not unlikely that the original 

 branchial vessels have effected a communication with the coelom" 

 (p. 385). 



Ich wende mich nun zu den Ergebnissen meiner eigenen Unter- 

 suchung. Dieselbe ist, wie Eingangs bemerkt, zu einem bestimmten 

 Zweck unternommen worden, und für diesen hatte die Feststellung 



1) Vgl. auch 8tiei)A, Ht.udien über den Amphioxus lauceolatus, in: 

 Mém. Acad. Imp. Sc, Pétersbourg (7), T. 10, No. 7, 1873, p. 61. 



