. Anatomischer Anzeiger. Anatomy, Comparative; Anatomy, Comparative. ()() away from the tonsils revealed the fact that they generally contain an unusual number of lymphocytes, as is indicated by the photographs reproduced as figures 7 and 8 and the drawing, figure 9. Within the tonsils themselves the vascular (venous) radicles are often completely gorged with these cells so that they are differen- tiated from the surrounding tissue only with difficulty. While this latter fact might be interpreted as due to a collection of lymphocytes from without, this seems hardly likely under the conditions.
. Anatomischer Anzeiger. Anatomy, Comparative; Anatomy, Comparative. ()() away from the tonsils revealed the fact that they generally contain an unusual number of lymphocytes, as is indicated by the photographs reproduced as figures 7 and 8 and the drawing, figure 9. Within the tonsils themselves the vascular (venous) radicles are often completely gorged with these cells so that they are differen- tiated from the surrounding tissue only with difficulty. While this latter fact might be interpreted as due to a collection of lymphocytes from without, this seems hardly likely under the conditions. The round cells do not seem to leave the tonsils by means of lymphatic but by venous channels. Although the sublingual tonsil in the toad is directly above a lymphatic sinus (ceratohyal sinus) only an occasional lymphocyte is found therein. Mitotic figures occur with fair frequency indicating that cell- proliferation is going on though not with marked rapidity. In the 86 mm specimen in the preglottideal tonsil, nearly every section contains in the tonsil a mitotic figure as many as four being found oc- casionally in a single section. Development. Because of the relatively late devel- opment of these structures, it is rather difficult to as- certain the morphological transformations that precede their appearance and which may be connected therewith. In fact in the case of the smaller tonsillar areas (I, II, V, VII, IX, XII) which have been spoken of as less constant in location and occurrence, the question of their morphogenetic cor- relations has not even been considered. While the developmental relations of the choanal tonsil (VIII) might undoubtedly have been determined, attention has in the present study been limited to the three most constant, namely, the preglottideal, lateral and sublingual tonsils (IV, III, VI). As has been previously stated, there is no trace of these structures in the larvae, nor indeed do they appear until transformation is fully. ® s® Fig. 9. Outl
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Keywords: ., bookcentury1900, bookdecade1910, bookpublisherjenag, bookyear1912
