1906] CURRENT LITERATURE 501 
forms, studying their morphological characters, and testing their relative value 
by parallel cultures. During the last five years the successive generations of 
these segregated pure races have been followed, with the result that a considerable 
number of mutants have been found and tested. In both papers DeVries 
compares NILsson’s pedigree-culture method with the older and still almost 
universal method of selection in which the undesirable individuals are destroyed 
and all the best are saved and sown together. He concludes that Rrimpavu could 
have produced the Schlanstedt barley, for which he is so widely celebrated, in 
four or five years by the Svaléf method, instead of having to devote to it the. 
20-25 years required by the older method. The magnitude and quickness of the 
results at Svaléf, where alone the conception of constant elementary forms has 
been adopted as the basic principle, indicates the importance of the newer con- 
ceptions of evolution for scientific agriculture, and these papers of DEVRIEs 
bring to the notice of the non-Swedish world methods which will doubtless lead 
to most important changes in the conduct of the various agricultural stations.— 
_ Gero. H. SHULL 
Report to Evolution Committee.—In a third report to the Evolution 
mittee of the Royal Society, BATESON, SAUNDERS, and PUNNETT?4 have s 
that practically all the complexities encountered in their study of hybrid sock 
sweet peas, and poultry are in essential accord with Mendelian expectation if 
the assumption is made that what appears externally as a single character may 
_be in reality dependent for its appearance upon the presence of two or more 
independent allelomorphs or internal units. In some cases the nature of these 
internal units is apparent, as when the presence of one always changes a pigment _ 
from red to blue; but in other cases there is no clue to the nature of the indi- 
| aan allelomorph, as when the combination of two white sweet peas sesaeed 
ce colored offspring owing to the bringing together of two allelomorphs 
Pinbined action of which is necessary to the production of color. In stocks ru 
sats 
of America (December 1905) the reviewer presented a paper on the “Latent 
characters of a white bean,” in which it was shown that the color of purple 
mottled beans obtained as an F, from a cross between yellow and white is depend- 
ent upon the simultaneous presence of three distinct allelomorphs. In that 
: pepe ity was ie predicted _— oo Ss ——* on — and sweet peas would 
e assumption of com- 
lex and inexplicable synth d resolution of "hypallomors as attempted 
in the earlier Reports to the Evolution Committee. The completeness with 
which the new point of view is demonstrated by these fecha | ath ah will © 
do much to strengthen the view that Mendelian behavior is a more common 
” 24 BaTESON,W., SAUNDERS, Miss E. R., PuNnerr, R. C, ay epost to the Evolu- 
tion Committee. III., pp. 52. London: Harrison & Sons. 1 
