250 



NATURE 



[July 30, 1874 



the ethmoid. The suspensorium is still greatly inclined 

 forwards, so that the quadrate lies immediately under the 

 ethmoidal region, and, consequently, the palato-pterygoid 

 and Meckel's cartilage, though lengthening, are still ex- 

 tremely short. The hyo-mandibular has completely 

 coalesced with the suspensorium, which is now therefore 

 a compound structure, and presents above two of the 

 three processes mentioned in the axolotl, namely the 

 pedicle (p) and the otic process (o), the latter at this 

 period Iselonging equally to both arches, the pedicle to 

 the mandibular only. The branchial arches have united 

 with one another above and below to form a perfect 

 branchial basket. The stapes (St) is now completely cut 

 out of the wall of the car sac, and the first ossification has 

 made its appearance on the base of the skull, in the posi- 

 tion of the para-sphenoid. 



5. In tadpoles in which the legs have increased greatly 

 in size and the tail has begun to shrink, a marked 

 advance has taken place in the proportion of the jaws to 

 the rest of the skull ; the mandibular pier has moved 

 downwards and backwards so as to lie at an angle of 45° 

 with the skull-flow, and the palato-pterygoid and lower 

 jaw are correspondingly lengthened. (Fig. 20 shows the 

 process further advanced.) The orbitar process is greatly 

 decreased in size and lies higher up on the suspensorium, 

 and the ethmoidal cartilage has sent out a vertical keel- 

 like plate (the septum nasi) between the olfactory sacs. 



6. The tadpole has now moulted its larval skin, so as 

 to expose the fore-limbs, and the tail is reduced to half its 

 original size. The walls of the brain-case, commenced in 

 the fourth stage, are now complete,and bytheirunion above 

 have formed a roof, interrupted only by their membranous 

 fontanelles, which are persistent in the adult, one in the 

 frontal, and a symmetrical pair of smaller ones in the 

 parietal region. The septum nasi is complete, and two 

 wing-like processes growing from it have inclosed the na?al 

 capsules by uniting with the floor formed by the greatly 

 expanded hypo-trabeculars. The hyoidean portion of the 

 otic process (Fig. 19, o) has now freed itself from its 

 connections, and appears as a triangular nodule of carti- 

 lage, the pharyngo-hyal (Fig. 20, Ph.Hy), or detached 

 apex of the arch ; at the same time the remainder of the 

 coalesced portion (Figs 18 and 20, H.M) begins to show 

 signs of separating once more from its union with the 

 mandibular pier. Besides the para-sphenoid, the parietal, 

 frontal, nasal, pre-maxillary, maxillary, squamosal, articu- 

 lar, and dentary ossifications have appeared. 



7 (Fig. 20). The skull of young frogs in which the tail 

 has just disappeared differs from that described in the 

 last stage, chiefly by the extension of the centres of ossi- 

 fication already mentioned, and the appearance in addi- 

 tion of the exoccipital, prootic, pterygoid, quadrato-jugal, 

 and septo-maxillary. The free portion of the hyoid (St. 

 Hy) has assumed the slender proportions which charac- 

 terise it in the adult, and it is united by fibre to the upper 

 part of the arch (H.M), which, although still fused with 

 the suspensorium, is marked off from the latter by a 

 distinct depression, and shows unequivocal signs of com- 

 mencing separation. 



8. A most important metamorphosis has taken place in 

 this stage, which includes young frogs just commencing 

 their first summer. The pharyngo-hyal or nodule of 

 cartilage separated from its arch in the sixth stage (see 

 Fig. 20, Ph.Hy) has now come into close contact with 

 the stapes, although it does not actually articulate with it 

 until the succeeding stage ; this freed apex of the hj'oid 

 arch thus becomes the inter-stapedial piece (Fig. 16, 

 p. 168, i.st) of the ossicula auditus, the representation of 

 the OS orbiciilare of mammals. At the same time the 

 next segment of the same arch (Fig. 20, H.M) has become 

 completely separated from its connection with the sus- 

 pensorium, and has taken on the form of the other three 

 elements of the chain of car-bones, the medio-, supra-, 

 and extra-stapedials (Fig. 16, m.st, s.st, e.st), which 



together are the homologue of the mammalian incus. 

 The malleus, although having its functional analogue in 

 the extra-stapedial (the end of the chain fitting into the 

 drum-menibr.ine) is represented morphologically by the 

 frog's suspensorial cartilage, being, as will be shown in a 

 future paper, the proximal end of the mandibular arch. 



9. The embryonic characters are now (first autumn) 

 fast disappearing. The suspensorium is at right angles 

 with the long axis of the skull, or almost exact half-way 

 between the positions it occupies in the seventh stage 

 (Fig. 20), and in the adult (Fig. 14, p. 168). The ossicula 

 auditus have come into union with the stapes, and the 

 stylo-hyal instead of being attached (as in Fig. 20) to the 

 suspensorium, has grown backwards to its adult position, 

 where, however, it is united only by fibrous tissue. The 

 parietals and frontals are still separate, and the maxilla has 

 not extended backwards to the quadrato-jugal, although 

 the fibrous space between them is now quite small. The 

 girdle-bone (Fig. 19, G) is singularly behindhand in its 

 ossification ; even at this stage it is represented only by 

 a slender plate of bone immediately anterior to the 

 frontals. At a further stage endosteal ossification sets up 

 in the cartilage on either side of this region, so that the 

 girdle-bone is formed by the coalescence of three separate 

 centres.* 



THE STRICKLAND CURATORSHIP IN THE 



UNIVERSITY OF CAMBRIDGE 



THE Vice- Chancellor of the University of Cambridge 

 has approved the nomination, by Miss Frances Strick- 

 land, of Apperley Court, of Mr. Osbert Salvin, F.R.S., to 

 the office of " Strickland Curator," lately founded and 

 endowed by that lady, and the Museum of that Univer- 

 sity will therefore reap the benefit of having attached 

 to it one of the best English ornithologists of the day. 

 Mr. Salvin, being then a scholar of Trinity Hall, gradu- 

 ated in mathematical honours in 1S57, and immediately 

 afterwards proceeded to join Mr. (now Canon) Tristram 

 in the natural history researches he was making in Al- 

 geria, the important results of which are known to many 

 of our readers. In the following autumn he sailed for 

 Central America, and there began that series of scientific 

 observations which has made him the chief authority on 

 the zoology of that part of the world. How many times 

 he has since visited it we cannot say, but he only returned 

 from his last expedition some two months ago, and he has 

 besides been all the while well occupied. In addition 

 to the many papers he has published, mostly on the birds 

 of the Neotropical Region, he has, in conjunction with 

 Mr. Sclater, brought out an illustrated "Exotic Orni- 

 thology," intended as a sequel to the celebrated works of 

 Daubenton and Temminck, and in 1S70 was cliosen 

 editor of the Ibis, the leading ornithological periodical 

 of the world. 



But our object here is not to sound the praises of Mr. 

 Salvin,who, it will be seen from what we have said,does not 

 requre them, but to point out the advantages that would ac- 

 crue to science if posts for the study and promotion of its 

 various other branches, similar to the recent foundation, 

 were established in our Universities. We are greatly 

 mistaken if the " Strickland Curatorship " is not the very 

 first step that has been made to.vards a fulfilment of that 

 idea of the endowment of research which has been often 

 urged in these columns, and was especially recommended 

 in the late Report of the Royal Commissioners on 

 Scientific Instruction and Aid to Science. Admitting 

 that the intention of Miss Slrickl.and was mainly to 

 secure the proper keeping of her late brother's ornitho- 

 logical collection, which was some years ago given by his 

 widow to the University, what will be the efi'ect of the 

 foundation ? The merely mechanical part of the curator's 



* It should li.Tve been slated in the last paper th.it Kig. 13 is taken from 

 a drawing kindly funiishcd by Prof. Hiixloy. 



