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Anatomy. — “Iemarks on the reticular cells of the oblongata in 
different vertebrates.’ By J. J. L. D. Baron van Hoeverr. 
(Communicated by Prof. L. Bork.) 
(Communicated in the meeting of January 28, 1911). 
The reticular cells in several mammals have been examined and 
described, and about some birds we have minute information from 
Casa"), while Mespac *) also gives excellent descriptions and illustrations 
of the large reticular celis in one species of bird (Gallus domesticus). 
In the reptiles, however, where the reticular cells are singularly 
conspicuous and characteristically arranged, these cells have never 
been described, nor have we any information of importance regarding 
the amphibians and various species of fishes *). 
A comparative study of the reticular cells has never been made, 
although these elements exhibit great differences in the vertebrate 
stem together with points of resemblance. Even in animals of the 
same class noticeable differences are found. 
It cannot be denied that, as long as so little is known with 
certainty about the nature and significance of the reticular cells, it 
would be somewhat rash to make comparisons, since the possibility 
of dissimilar quantities being compared with each other is not 
excluded. In my investigations I have confined my attention princi- 
pully to the largest reticular elements, because these are the most 
fit for comparison. Still less is known of the small reticular cells 
than of the largest. A sharply defined boundary of the larger reticular 
cells from the smaller is, however, not always possible as yet. Besides 
the large reticular cells, therefore, I have traced the smaller ones 
also as much as possible, although the chief aim of my research was 
the arrangement of the larger elements. | have examined series of 
frontal sections coloured after van GrgsoN or with carmine. 
The animals which I examined were: 
one cartilaginous fish: Raja: 
one amphibian: Rana; 
') Contribucion al Estudio de los ganglios de la substantia reticular del bulbo. 
Trabajos del laboratorio de Investigaciones biologicas. Tomo VII fase. 4°. 1909. 
*) Bijdrage tot de ontwikkelingsgeschiedenis van de structuur der hersenen bij 
het kippenembryo. Inaugural Dissertation. Groningen 1909. 
5) Special mention must be made of the large cell elements of the oblongata 
in the Cyclostomes, lately described by Tretsaxorr Whether the large Mullerian 
cells of the Cyclostomes are to be classed with the large reticular cells of the 
bulb of other animals is not certain, bnt there is much which pleads for a homology 
(Cf. Trersaxorr: Das Nervensystem von Ammocoetes. IL. Gehirn. Archiv. für mikro- 
skopische Anatomie und Entwiekelungsgeschichte. Vol. 74, 1909). 
