Boyal Microscopical Society. 211 



II, — 071 the Form and Use of the Facial Arches. 



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



(Bead before the Eoyal Microscopical Society, Oct. 4, 1871.) 



Plate CII.— C. 



Having had an unusual amount of leisure this summer, I have 

 been able to work with the microscope once more, and thus be the 

 recipient of no Httle pleasure and profit ; but, as my time is very 

 swift- winged, it is not proper that I should run from one pretty thing 

 to another. I have had, this time, one subject — the Salmon's Skull. 



Those who consider the salmon from merely a dietetic point 

 of view will be shocked to hear that my friends, Messrs. Water- 

 house Hawkins, F. Bucldand, and Henry Lee, have, together, 

 supplied me with some two hundred specimens. These, however, 

 were not full-grown individuals, but fry and embryos, as yet 

 unhatched. These last have lost their chance of living as salmon, 

 but I hope that they, many of them, will live for ever in the 

 Transactions of the Koyal Society ; their portraits and descriptions 

 of their personal appearance will be offered to that great good 

 mother of all our Scientific Societies. 



It occurred to me, however, that a sketch of the face of one of 

 these water-babies might be acceptable to this pleasant daughter- 

 society. 



And here let me say that, when once we know all about the 

 face of infantile salmon, we shall be well prepared to discuss 

 the form of the first foundation of our own face and features. 

 I have not made many alterations in my mode of working this 

 time, but one or two " wrinkles " have been developed. 



Fu-stly, it is better to preserve the eggs and fry in strong 

 spirit, and then to place them in a solution of chromic acid for 

 a week or two before they are dissected ; except in some instances, 

 when I want to use high power on thin slices as transparencies, I 

 eschew glycerine. It is better to keep the little preparations in a 

 watch-glass, still preserved in a solution of the acid. This saves 

 them from losing their good yellow colour; in glycerine they 

 become bluish- white, and are bad for examining as opaque objects. 



Another thing is the comfort of using only clean water ; great 

 irritation of the nerves, to say nothing of the temper, is apt to be 

 produced by the discomfort of feeling one's fingers sticky when 

 working with the glycerine. This is no little matter to a worker 

 with the microscope, for the eyes and brain become intensely weary 

 in such sharp-sighted researches, and the least interruption is apt 

 to injure the calmness of the olDserver when he is highly strung. 

 One most excellent eff'ect of the chromic acid is, that it preserves, 

 and even increases the lilac tint of hyaline cartilage ; that it makes 



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