Miscellaneous, 259 



nised filaments ("fibres") having the same remarkable appearance 

 as those which Dr. Barry had previously shown to him in muscle. 



On a subsequent occasion — several physiologists being present, 

 one of whom was Professor Owen — there were seen muscular 

 ** fibrillse," not only flat, grooved, and compound, but separated at 

 the end into their single and simply spiral threads, — the really ulti- 

 mate threads of muscle. In this instance chromic acid was substi- 

 tuted for the reagent above-mentioned (Annals, vol. viii. p. 546.) as 

 usually employed by Dr. Barry in these researches : and for the exa- 

 mination of muscle he now finds the chromic acid to be even pre- 

 ferable thereto*. 



To find the muscular " fibrillse " of a size proper for examination, 

 and so loosely held together that they may be separated with ease, 

 the heart of a fish or reptile should be employed. Dr. Barry has 

 used the heart of various fishes, as well as that of the turtle, newt, 

 and frog — and chiefly the frog. 



To find those states of voluntary muscle in which the transverse 

 striae are produced by the windings of comparatively large interlaced 

 spiral filaments (see abstract of the postscript to Dr. Barry's paper 

 " On Fibre," p. 506), he recommends muscle from the tail of the very 

 minute tadpole — ^when this larva is only 4 or 5 lines in length (as at 

 the present season) — or muscle from the leg of a boiled lobster, as 

 being very easily obtained. In these states of muscle, the interla- 

 cing spirals are seen to dip inwards, towards the centre of the fasci- 

 culus, in a manner that may be represented by making the half- 

 bent fingers of the two hands to alternate with one another, and then 

 viewing them on the extensor side. 



To find the filament in red blood-discs. Dr. Barry recommends the 

 blood of a batrachian reptile, such as the frog or newt, on account 

 of the large size of the discs in these animals. The blood should be 

 examined just before its coagulation, as well as at various periods 

 during the formation of the clot. Dr. Barry has usually added one 

 of the above reagents, or nitrate of silver. 



TEMPERATURE OF COLD-BLOODED ANIMALS. 



M. Dumas, in requesting the Academy to add some new members 

 to the commission charged with the examination of the memoir of 

 M. Valenciennes and of that of M. Lamarre-Picquot, from some 

 remarks of M. Dumeril which seemed to require an extension of 

 the discussion, stated that the question was, in fact, to consider 

 a point of physiology of the highest interest ; for we may conclude, 

 from the investigation of MM. Lamarre-Picquot and Valenciennes, 

 that certain cold-blooded animals may, in given circumstances, 

 become warm-blooded animals, in the same way that certain warm- 

 blooded animals, the hibernating animals, become, in given circum- 

 stances, true cold-blooded animals. The question then is, to clear up 

 this point of physiology, and to ascertain whether, in the same way 

 that certain warm-blooded animals are able to support a lowering of 



* We are indebted to Dr. Hannover for bringing into notice the use of 

 the chromic acid for such purposes. 



