ORIGIN OF J'HOSPItOIUS COMPOUNDS IX HENS' EfiGS 283 



the assumption (hat tho vohunr of blood of the hon iiniounl(>(l to 150 cc. and tho 

 volume of tho hlood plasma to 100 eo. 



Table 9. — Spkcific Activity' and I'otal Phosphori's Contkxt 



OF THK IIkn's Blood 



I Specific 

 Fraction 



I 



activity 



Total pliosphorus 

 content 



Plasma inorganif (1.0104 ! 5.4 



Plasma phosphatide 0.012r, j 20.0 



Corpuscles phosphatide 0.004f) 1 1.3 



Corpuscles acid .soluble i 0.003<'> ^O.r, 



Corpuscles protein 0.0031 j I.k'J 



That the specific activity of the plasma phosphatide P is greater after 28 hoiiis 

 than that of the inorganic P is due, as discussed on page 279, to the rapid disappoa- 

 i-ance of the individual inorganic P atoms from the plasma. In the experiment 

 discussed on page 286, in which the hen was killed only 5 hours after the admi- 

 nistration of the labelled P, the specific activity of the phosphatide P was found 

 to be only 42% of that of the inorganic P. 



It is of great interest that the specific activity of the plasma phosphatide P 

 is several times larger than that of the corpuscle phosphatide which shows that 

 a much smaller percentage of the corpuscle phosphatide than of the plasma phos- 

 phatide is renewed in the course of the experiment. This is an interesting result 

 as it definitely disposes of the often discussed possibihty that the blood phospha- 

 tide is synthetised in the corpuscles. Some of the corpuscles being formed during 

 the experiment from labelled plasma are bound to contain labelled phosphatides; 

 labelled phosphatides can furthermore easily get into the stroma of the corpuscles 

 which are partly composed of phosphatides. 



A very suggesting change in the phosphatide content of hens blood at the 

 time of production was ascertained by Heller, Paul, and Thompson (comp. 

 Fig. 1). The most interesting feature of the curves recorded by them is a gradual 

 increase in the total P of the blood at the time of production, this high level being 

 held during the entire production period with some fluctuations and dropping 

 quickly as production ceases and molting season approaches. The increase is duo 

 to that of the lipoid P and is much more conspicious in the case of the plasma 

 than in that of the corpuscles; the lipoid P content of tho plasma is higher all 

 through than that of the corpuscles, at the peak of production tho foi-mer value 

 being nearly throe times higher than the last mentioned one. As about 2/. ^ of tho 

 blood volume is composed of plasma it follows, that from the total lipoid P present 

 in the blood ^/g arc to bo found in tho plasma. The predominance of phosphatide 

 i' ir the plasma found for laying hens is entirely unique as seen from the figures 

 of Table 10, but understandable if we envisage the great strain put on the organism 

 of a hen as to lecithin suppl;^'. A hon laying daily has to produce about (50 mgm 

 lecithin! P a day: taking a total plasma volume amounting (o 100. cc the total 

 lecithin P of the plasma works out to be 20 mgm. If (he loc^hhin found in the yolk 

 is, as suggested from our tosuKs, taken from the plasma lecithin tlu n the plasma 

 has to give off three times its total lecithin content in tho course of a day thus 



1 Lecithin plus other phosphatides. 



