1908. | Note on the Nutrition of the Karly Embryo. 335 
albumoses, peptones, etc., in the egg-white of developing eggs. The 
methods adopted were: (1) To shake up the insoluble white with distilled 
water; through the coagulated interface the albumoses and peptones passed 
into solution and gave a well-marked biuret reaction. (2) To add 10 times 
its bulk of absolute alcohol to the egg-albumin, to stir thoroughly, allowing 
the alcohol to remain for at least seven days. At the end of that time all 
the albumins and globulins were coagulated and the albumoses and peptones 
precipitated. On washing the filtered mass with distilled water, the latter 
were rendered soluble and passed out into the filtrate, where they were 
examined. From the sixth day onwards distinct evidence was obtained by 
means of the biuret reaction of the presence of albumoses and peptones. 
Examination of the yolk and of the amniotic fluid by the same means failed 
to elicit their presence in these substances. 
Occasionally, it may be remarked, the biuret gave a reduction on standing, 
also obtained on boiling. The phenomenon was as follows:—The rose pink 
appeared readily, to quickly become a brown solution; on standing, the brown 
was precipitated in the form of a flocculent precipitate, the pink colour 
returning to its original shade when the precipitate had settled (at the end 
of 18 hours). What this reducing agent is 1s not known, it is improbable 
that it is a form of sugar. 
J. Starke has carried out an experiment which may be referred to here. 
He found that if a greatly diluted albumin solution, any pre-existing 
globulin having been removed by filtration, is kept at 56° C. or over for 
some little time, it contains a proteid with the following reactions :—(1) It is 
precipitated by COs, acids, and the addition of a very small quantity of 
alkaline-earth salts. (2) Precipitated by dialysis. (3) Can be salted out 
by MgSOsNaCl.KCl. (4) Soluble in dilute alkalies and very dilute acids 
with absorption of the same. (5) Insoluble in HO and dilute neutral salts 
(it dissolves in the latter only if a trace of alkali is present). (6) It holds 
less ash than albumin. (7) It contains less sulphur than albumin. (8) It 
contains more water than coagulable proteid. (9) It is not heat coagulable. 
(10) It forms an opalescent solution like all globulins. (11) It sets free 
more reducing substance on boiling with acid than albumin. (12) It is 
sensitive to the influence of salts in an acid solution, not in an alkaline. 
(13) The neutral salts play, under the same circumstances, a 7dle such as 
they do with globulins. 
Examination of unfertilised eggs which have been incubated along with 
the fertilised shows that no material change has taken place in the reactions 
of the egg-white of the former, and so heat alone cannot be said to be the 
cause of the changes noticed in incubating developing eggs. Again, whilst 
VOL. LXXX.—B. 2D 
