( 1055 ) 
More frontally from Fig. LL, we again find a less lateral arrangement 
of the large reticular cells and the number met with per section 
also diminishes. Fig. 12 represents a section through the praetrige- 
minal region of the oblongata of the Alligator. The section here 
shown passes through the posterior pole of the tubereulum quadri 
geminum posticum and also intersects the [V nucleus. The arrangement 
of the large cells, as occurs here, in the middle of the diameter 
of the bulbus, continues frontally to the end of the series of reticular 
cells, i.e. to behind the [IL nucleus, where the large reticular cells 
are sporadic The raphe nucleus with small cells, whieh can also 
be seen in fig. 12, ceases on nearly the same level as where the 
large reticular cells become sporadic. These raphe-cells maintain 
a more independent character with regard to the other reticular cells. 
Chelone Midas. 
Chelone differs in many respects from Alligator. In the caudal 
part of the oblongata it shows some resemblance to the latter as 
regards the appearance of the reticular cells. Nor is the praetrigeminal 
region markedly different from that in Alligator. On the level of 
the entering VIII and V roots, however, an entirely different aspect 
is presented. Following the same order as I took in examining the 
other animals I can state the following details about the reticular 
elements of Chelone: On the level of entrance of the X roots, one 
reticular nucleus is found, which resembles the nucleus found in that 
region in the Alligator in so far as the large reticular cells are arranged 
in the same way in the raphe and along the lower and side border of 
the fase. long. post. In Chelone, however, no reticular cells are spread 
so far laterally in the formatio reticularis. Also the groups /, and J, of 
Alligator (PL. 6, 7 and 8) are wanting in Chelone. The reticular group 
of the vagus region is sharply limited orally, owing to the fact that, 
on the level of the extrance of the VIII, large reticular cells occur 
only sporadically and but a few smaller reticular cells are present 
there"). On the level of the motor trigeminus nucleus on the other hand, 
there is a cluster of large reticular cells, not only along the lower 
and outer border of the fase. long. post, but also in the raphe, 
which L did not find on this level in other animals. (See fig. 13). 
On the level of the caudal half of the motor V nucleus the large 
cells are even found principally in the raphe; on the level of the 
frontal half of this nucleus, however, there are as many lateral in 
') The ne. Deiters is well developed. | found no oliva superior. 
69* 
