54t) H. H. SWINNEKI'ON. 



the stickleback), lias been quite suppresssed, or is merely 

 represented in pro-cartilage. McMurrich compares this 

 " ethmo-palatine " with that cartilage spoken of by Parker 

 as the " pterygo-palatiue.'^ Shortly before he wrote his 

 paper, however, Stohr showed that Parker's description was 

 erroneous, and that the so-called pterygo-palatine, i. e. the 

 whole of the palatine process, was never separate from the 

 quadrate, though its slender connection with that rendered 

 it liable to be torn away. This is just what Parker did. 

 Entering into the development of this region in greater 

 detail, he described a ledge of pro-cartilage near the inner end 

 of the maxilla^ not far from the end of the trabecula. This, 

 he says, may chondrify separately, and may fuse with the 

 extremity of the " pterygo-palatine " or palatine process. 

 Thus Parker's separate element does not exist, and even if it 

 did, it would be something entirely diiferent from the 

 inconstant element described by Stohr. Pollard, working 

 upon the cartilages in the head of Siluroids, describes a 

 separate element which lies upon the upper end of the maxilla 

 in front, and may fuse with the ethmoid beliind ; this has, 

 therefore, all the essential relations of the maxillary process. 

 He calls it the pre-palathie and says, " This piece is well 

 known (Stohr and Parker) to arise m Teleostei independently 

 of the cartilaginous upper jaw " (94, p. o56). Prom this it is 

 evident that he misunderstood Llie description of these two 

 authors. His ability to speak of the pre-palatine as arising 

 independently is wholly due to the course he pursued in 

 making his models, for he represented only those portions 

 which were still cartilaginous, and neglected those which 

 were osseous, even though they might possibly have replaced 

 cartilage developmentally. If the same had been done for 

 the ethmoid and palatine in hg, 9, the palatine bone would, of 

 course, have been omitted, and the real extremity of the 

 palatine process would have appeared as a cartilage, wholly 

 independent of the cartilaginous upper jaw, but continuous 

 with the ethmoid. This, however, would give an absolutely 

 false idea of the parts. Examination of sections through the 



