194 J. B. JOHNSTON, 
of the brain anterior to it. I use the term in the same sense as 
the German Bindearm when used in its widest meaning. This 
word has been used in such a great variety of senses that it should 
be avoided. These tracts pass in Acipenser through a comparatively 
narrow bridge of tissue connecting the cerebellum with the lateral 
walls of the mid brain and medulla. I have given on page 135 a 
summary of the tracts which enter the cerebellum by way of this 
bridge. It would not be profitable to collect all the statements in 
the literature concerning these tracts for purpose of comparison, 
since my statement is such that the comparisons can readily be 
made. I shall, however, compare one or two of the more recent 
descriptions of this crus, although these as well as earlier ones have 
been more or less fragmentary. EDINGER described the Bindearm 
in his first “tween brain paper (92) as follows: “Etwas lateral und 
caudal [from the fasc. long. post.] entspringen die Processus ad cere- 
bellum, die Bindearme. Man sieht sie jederseits nahe der Hirnbasis 
bis fast an die caudale Grenze des Mittelhirns ziehen. Da wenden 
sie sich plötzlich medianwärts und kreuzen in einer mächtigen 
Kreuzung — Bindearmkreuzung — mit den gleichen Fasern von 
der andern Seite. Nach der Kreuzung ziehen die Bindearme in das 
Cerebellum. Bei keiner Thierart konnte der Ursprung und der voll- 
ständige Verlauf der beiden letzt genannten Bündel mit der Sicher- 
heit festgestellt werden, wie es bei den Selachiern möglich war.” 
In Amphibia the Bindearme, “dorsal vom Abgange des Infundibulum 
vom Zwischenhirn entspringend”, run caudally, become compact 
bundles which cross behind the III nerve, and enter the cerebellum. 
In the 5th edition of the Vorlesungen EDINGER applies the name 
Bindearm to the tractus tegmento-cerebellaris, from the nucleus 
ruber tegmenti, crossing at the level of the III nerve. In the 
Teleosts, EDINGER says in the same paragraph, two tracts go from 
the “tween brain, “ein feinfaseriger caudaler und ein starkfaseriger 
frontaler Zug, der erstere in das Cerebellum, der letztere in den 
als Valvula cerebelli bezeichneten Abschnitt unter dem Mittelhirn- 
dache, Tractus diencephalo-cerebellaris”. In his last ‘tween brain 
paper (’99) he uses the term Bindearm in the same sense but says 
that the decussation was not seen. In the next paragraph he 
mentions other bundles which arise in part from the mid brain and 
in larger part from the trigeminus nuclei and enter the front part 
of the cerebellum, crossing in the velum just before sinking into 
the substance of the cerebellum (Decussatio veli). 
