154 
Anton Dohm 
when the gills on the hinder arches have reached their full develop- 
mentAi 
So gewann auch bei der embryologischen Untersuchung das 
Problem keine Förderung, nur glaubte Balfour, die frühzeitige 
Atrophie des Spritzloches bewiese gegen Joh. Müller. 
Endlich aber versuchte ein transatlantischer Forscher, Prof. 
Ramsay Wright in Toronto (Canada), die Frage direct zur Lösung 
zu bringen. Vielleicht habe ich selbst dazu einen Theil des Anstoßes 
gegeben durch meinen Widerspruch gegen die Gegenb aur' sehe Deu- 
tung der Pseudobranchie, wie wenigstens der Verf. auf p. 477 (»On 
the hyomandibular clefts and Pseudob ranch s of Lepidosteus and 
Amia. Journ. of Anat. and Phys. 1885) andeutet, und hinzufügt: 
ut cannot he doubted but that the condition of the parts in Lepido- 
steus and especially in Amia, when thoroughly elucidated, will defini- 
tely settle this questiona Ob das Prof. Wright gelungen, möchte 
ich indess bezweifeln, und will nun seine Beweisführung wiederzu- 
geben suchen, und meine Kritik derselben beifügen. 
Auf p. 484 sagt der canadische Forscher: 
»The Arteria hyoidea arises from the ventral end of the effe- 
rent artery of the first branchial arch, as suspected by Müller. 
It gains the lateral or anterior aspec*t of the hyoid arch, and then 
divides into an anterior lingual and posterior hyoid portion. The 
latter runs bachwards and upwards along the outer border of the 
hyoid arch, tili it reaches the interval between the epihyal and sym- 
plectic , where it aecompanies the r. hy o ideo - mandibular is VII. 
It does not reach the inner aspect of the gill-cover, however, by an 
aperture similar to that in Teleosts , but anastomoses with a vessel 
Coming thence through the interval between the hyomandibular and 
interhyal, the origin of which may now be described. 
»Müller does not discuss the fate of the blood which is aerated 
in the opercular gill. Its afferent artery, after running along the 
inner or posterior aspect of the hyoid arch, is distributed in the ca- 
pillaries of the gill, whence the aerated blood is collected by an effe- 
rent artery, which curves forwards towards the outer aspect of the 
gill-cover, and anastomoses with the art. hyoidea, in the manner des- 
cribed above. From this anastomosis is developed the afferent artery 
of the hyoidean pseudobranch , which bends over the symplectic to 
reach the inner aspect of the gill-cover, running bachwards to its 
distribution in the filaments of the pseudobranch. The efferent artery 
of the pseudobranch runs forwards in the roof of the mouth and 
