THE 



MONTHLY MICROSCOPICAL JOURNAL. 



MAY 1, 1871. 



I. — On the Mode of Worhing-out the Morphology of the Skull. 



By W. Kitchen Parker, F.K.S., President K.M.S. 

 {Read htfore the Koyal Microscopical Society, April 5, 1871.) 



A VERY large amount of information with regard to the structure 

 of the vertebrate skull may be obtained by the use of the ordinary 

 methods, maceration, dissection, &c., with the aid of the pocket- 

 lens. A huge mass of anatomical literature exists in which the 

 development of the skull has been thus traced, say half-way down- 

 ward. The value of all this is greatly depreciated by the fact that 

 the first half of the development processes have not been traced. 



Thus we are reading a language only the last twelve of the 

 letters of which have been seen by us. Even as to mere ossific 

 centres, a very secondary matter in the structure of the skull, only 

 about two-thirds of those which may be found in the bird have, 

 until very lately, been described. In my paper " On the Fowl's 

 Skull," published in the ' Philosophical Transactions ' last year, the 

 skull is traced back to a stage answering to Professor Huxley's 

 fig. 57, F and F', in his ' Elements of Comparative Anatomy ' 

 (see p, 138). Later researches on the growth of the skull of the 

 common frog have shown me that my earliest stage of the fowl's 

 skull had akeady undergone a large amount of metamorphic change. 

 I can now understand what those changes were, but to make them 

 plain a series of less mature embryos must be worked out. 



For many years my embryonic subjects had been prepared by 

 being hardened in strong methylated sj)irit ; but this never was 

 sufficient in the earlier conditions, and I sufiered much loss of time 

 and specimens. Spuit specimens, when examined in section, require 

 to be treated with caustic potass or soda, and then jjut into glycerine. 

 In this way fine razor slices can be examined with the quarter-inch 

 object-glass, and even with the highest eye-piece. I generally, 

 however, use the middle eye-piece. Transverse sections show most ; 

 and slices passing from before backwards, and thooughly illus- 

 trated and tinted, show very much indeed. I refer again to my 

 paper " On the Fowl's Skull," in which the original figures have 



VOL, V. Q 



