1885.] OF THE HUMAN SPHENOID BONE. 585 



lingulffi of mammals. In the same specimen the hasitetnporal bones 

 are present. The skull of this Ostrich is sufficient in itself to prove 

 that the cenclusions of Mr. Parker regarding tiie identity of the basi- 

 temporals of birds and the mammalian lingulse spheuoidales are based 

 on erroneous premises. 



It now behoves me, seeing that I challenge these views, to identify 

 the lingulae, and explain the apparently anomalous condition of the 

 basitemporals. 



I shall address myself to the lingulse first. In the skull of certain 

 fish there is a centre known as the sphenotic, which occupies the 

 antero-external region of tlie periotic capsule, but the cartilage in 

 which it arises is always of a composite character, being due to the 

 confluence of proper cranial cartilage with that of the periotic 

 cartilage. This centre is firesent in the Fowl in the very spot 

 where the lingulse ought to he represented. 



In the chondro-oranium of Man, the cochlear region of the 

 periotic capsule comes into union with the lingulse of the sphenoid, 

 and the remains of the uniting cartilage are familiar to students of 

 human anatomy as the cartilage filling up the foramen lacerum 

 medium. If the cartilaginous lingulse of the bird and man are 

 homologous, and on that score there can be no doubt, then the ossific 

 nuclei which transform them into bone should certainly be considered 

 homologous also. On these grounds my contention is, that the 

 nuclei called sphenotic in the Fowl and Ostrich are the true 

 morphological representatives of the human lingulae. It is now 

 necessary to find out to what ossifications in the mammalian skull 

 the basitemporals of the bird really correspond. 



Turn from the Bird for a brief space, and inspect the hard palate 

 of a Crocodile. From before backwards we find the following bones: — 

 premaxilla, prepalatine portion of the maxilla, palate, and a bone 

 usually marked pterygoid ; passing from the outer edge of this bone 

 to the maxilla is a bony bar known to anatomists as the os transver- 

 sum, the general relations of which can be readily seen by reference 

 to Plate XXXV. fig. 4. 



The anatomical relations of the bone marked pterygoid are impor- 

 tant in the following particulars : they surround the posterior nares, 

 it being due to their intervention that the nasal passages are pro- 

 longed posteriorly to such a marked extent in the Crocodile. Above, 

 they have the Eustachian passages, and externally they support the 

 OS transversum. This latter bone ought to be really regarded as the 

 pterygoid. In Man's skull, and it is most probably true of other 

 mammals, the internal pterygoid arises as an ossification of the distal 

 end of the palato-pterygoid cartilage. The bone in the Crocodile's 

 hard palate marked pterygoid arises as a membrane-bone, and during 

 its growth the outer end invades to a slight extent the middle portion 

 of the palato-pterygoid cartilage, and thus cuts off the distal end of 

 the chondral rod, which becomes the os transversum, really the in- 

 ternal pterygoid. 



Even at the risk of being tedious I must make myself clear on this 

 point. In Man a rod of hyaline cartilage stretches from, and is con- 

 tinuous with, the malleus at the eighth week of intra-uterine life ; it 



