76 H. C. SORBY. 



in its general results. As regards the peculiar refractive 

 qualities, however, which are impressed upon the tissue 

 elements by the modified carmine process above described, I 

 may state my belief that this will yet prove of most essential 

 service in the estimation of the relative proportions of cell- 

 processes in any individual section, and the most accurate 

 tracing of any existing connections, for not by the deepest 

 aniline staming have I yet succeeded in demonstrating the 

 existence of so thick and numerous a series of processes 

 diverging from the pyramidal layers of the cerebral cortex as 

 by the methods described above. With regard to the smaller 

 cells of the cerebrum and cerebellum the logwood staining 

 is eminently successful ; but when it is our object to bring 

 into view the larger cells and their extensions, I would 

 recommend the aniline dyeing above described, or the double 

 staining with logwood and aniline. 



On the Evolution of Hemoglobin. By H. C. Sorby, 

 r.R.S., F.L.S., F.Z.S., President of the Royal Micro- 

 scopical Society. 



In a paper read before the Royal Microscopical Society 

 last April, published in the 'Monthly Microscopical Journal ' 

 for May,^ I endeavoured to show the very great importance 

 of referring all the measurements of spectra to the wave- 

 lengths of each part expressed in millionths of a millimeter ; 

 and in another paper read before the same Society in 

 November, published in the above-named journal for 

 December,^ I described a new form of apparatus by means 

 of which the wave-lengths can easily be measured to a mil- 

 lionth of a millimeter, and the difference in the wave- 

 lengths of the centre of the bands in closely related spectra 

 determined with still greater accuracy. In the former paper 

 I also endeavoured to point out the very important con- 

 clusions which may be drawn from those small differences 

 in the position of the absorption-bands, which might easily 

 be overlooked, and which in some cases I had myself over- 

 looked until quite recently. Unfortunately the full meaning 

 of some of these differences cannot yet be ascertained with 



1 Vol. xiii, p. ]98. 



2 Vol. xiv, p. 2G9. 



