AVIAN ost::ology. 397 



attention to the fact that the tendon of the ambiens miiscle 

 passes through the patella in Cormorants, he uses the word 

 " perforates" (emphasizing it by the use of italics). Surely he 

 could not have meant that the tendon really did " perforate " or 

 bore its way through the patella as the Cormorant grew and 

 developed ? And, after finding its w^ay through the bone (or 

 cartilage) that it duly made attachment at its point of insertion ? 

 ISo such thing has ever occurred in anatomical development, and 

 Forbes was altogether too good an anatomist to have set up any 

 such ridiculous explanation. This being true, arid disregai'ding 

 entirely any such theorj^ or such another possible suggestion as 

 that, in suhadult life, the patella of a Cormorant, forming first 

 in elementary cartilage, does, when in that condition, surround 

 the tendon of the ambiens muscle, and afterwards, when the 

 patella has completely ossified in old birds, the aforesaid tendon 

 runs through a foramen, which passes through the middle of 

 it. Barring this, too, as I say, as being a totally untenable sug- 

 gestion, we are left with but two other possible ways by means of 

 which the ambiens comes to pass through the foraminal canal in 

 the patella of Cormorants. 



In discussing these, we are at once confronted with Garrod's 

 opinion in regard to it — an opinion which had never, apparently, 

 occurred to Forbes. GaiTod took the vieAv that, inasmuch as 

 in anhinga (Flotus) the anterior face of the patella is somewhat 

 deeply grooved, and as ligament stretches across that groove to 

 confine the tendon of the ambiens muscle which passes through 

 it, and as this same ligament sometimes " shows traces of ossi- 

 fication," — hence in Cormorants this also takes place, and the 

 fibrous ligament in them becomes, in old individuals, thoroughly 

 ossified, and we thus find the tendon of the ambiens passing 

 through the bone. 



Such an opinion will not hold for an instant in the face of the 

 necessary material to examine into it. 



Now in some Cormorants the patella is very large and thick, 

 and the aforesaid foraminal passage, passing through it from side 

 to side, is found but slightly in advance of the middle and above 

 the centre of the bone ; so that, had it been a "gi^oove" in the 

 young bird spanned by fibrous ligament, and this ligament sub- 

 sequently ossified in the adult, that groove must have been a very 

 deep one, and the patella in old birds w^ould, through its form 

 alone, after ossification was complete, exhibit the manner as to 

 how it had come about. Moreover, in connection with this it is 

 very clear that, were the foramen in the patella in Cormorants 

 formed by a groove in front of it being covered over by fibi-ous 

 ligament in the subadult bird, which ligament later in life ossified, 

 that ossification would be smooth on its anterior face, which is by 

 no means the case, as one may see by a study of the figui'es in the 

 plate accompanying this paper. For instance, a fibrous ligament, 

 sti'etching across a deep, narrow groove as a retaining band for 

 the tendon of a muscle, would not, in ossifying, take on any other 

 shape beyond that possessed by the flat ligamentous band ; for 



