334 
rorULAR SCIENCE RE7IEW. 
of the annelids (like Nereis) are peculiar in possessing a number of lateral 
processes. In others the sarcolemina is indicated, though it may of course 
be asked in how far it is a post-mortem or artificial structure, or how far it 
is represented by the connective tissue which unites the muscular fibres 
together. 
Cohesion of the. Blood- Coi'puscles. — As to this singular phenomenon, 
Professor Norris, of Birmingham, gives the following account in a paper quite 
recently communicated to the Eoyal Society. My idea of the blood - 
corpuscle is that its contents are something essentially different, so far 
as cohesive attraction is concerned, from the liquor sanguinis, that is to say, 
not readily miscible with liquor sanguinis. This is of course self-evident, if, 
according to some modem views, we regard the corpuscles as tiny lumps 
of a uniformly viscous matter,” inasmuch as such matter must be insoluble in, 
and immiscible with, the liquor sanguinis. The explanation is equally easy, 
if we accept the old and, I believe, the true view of the vesicular character of 
these bodies, as we have only to assume that the envelope is so saturated with 
the corpuscular contefits as practically to act as such contents would them- 
selves act, i.e. to exhibit a greater cohesive attraction for their own particles 
than for those of the contiguous liquid. The cohesive power of the blood- 
corpuscles varies with varying conditions of the liquor sanguinis, and this is 
doubtless due to the law of osmosis; for we can readily imagine that when 
the oxosmotic tendency was in excess the corpuscles would become more 
adhesive, and, on the contrary, when theendosmotic current prevailed, less so. 
In any case the increased cohesiveness will be due to the increased extrusion 
upon the surface of the corpuscular contents. All, then, that is required in 
the case of tlie blood-corpuscles is a difference between their liquid contents 
and the plasma in which they are submerged. That this difierence is not 
so great as between the liquids used in these experiments is probable, but it 
must also be remembered that the attraction is not so powerful. The power 
required to attach the blood-corpuscles together is, on account of their 
exceeding minuteness, extremely small, as they are thus so much more 
removed from the influence of gravitation, and brought under that of mole- 
cular attraction.” 
The Colour ituj Matter of the Feathers of the Turaco . — This substance, 
which has been especially examined by Professor Church, is thus described 
by liim in the Proceedings of the Royal Society. It is a remarkable red pigment, 
extracted from four species of Turaco, or plantain-eater ; it occurs in about 
fifteen of the primary and secondary pinion feathers of the birds in question, 
and may be extracted by a dilute alkaline solution, and reprecipitated with- 
out change by an acid. It is distinguished from all other natural pigments, 
yet isolated by the presence of fi-0 per cent, of copper, which cannot be re- 
moved without the destruction of the colouring-matter itself. The spectrum 
of turacine sliows two black absorption-bands, similar to those of scarlet 
cruorine ; turacine, however, differs from cruorine in many particulars. It 
exhibits great constancy of composition, even when derived from different 
genera and sjwcies of plantain-eater ; as, for example, the Musophaga viola- 
cca, the Corythaiv alho-cristata^ and the C. poiphyreolopha. 
The Chair of Physiology at Bartholomew’s Hospital, lately vacated by 
Mr. W. S. Savory, P.K.S., has been given to Mr. Morrant Baker. 
