No. 3, December, 1920] GENETICS 1G3 



great importance. In tin's paper the writer has indicated the necessity of .sharply distinguish- 

 ing two different views of relationship; relationship in descendance or genealogic relation- 

 ship and relationship in capacities, gentoypic relationship. These two sorts of relationship 

 may not be confounded in modern literature of genetics as has till now been done by many 

 writers; they are not at all identical; two mdi\ i duals may in genealogical sense be very nearly 

 related, though their genotypes are highly different; inversely the genotypes of two indi- 

 viduals can be identical, however t hey don't show any genealogical relationship. In t he great 

 lines of phylogeny a narrow tie will perhaps have bound these two relationships, but the pres- 

 ence of the one is not even an indication for the other's appearance. — Now it will be a subject 

 of a great many researches to find good methods for establishing these relationships: the 

 ancient method of portrait-building and comparing is no longer sufficient. Experimental 

 methods only can be accepted. But not all the researches, called experimental, are really 

 experimental. Really experimental methods for proving the existence of genealogical rela- 

 tionships may be found easily; systematic breeding and a well-developed administration is 

 the only means of getting an insight into genealogical relationship. Demonstration of geno- 

 typic relationship however is not so easy; till nowadays we have only breeding methods, and 

 we can state genotypic relationship only by means of systematic crossings. This method 

 however is in its possible usefulness very limited; in practical sense it has been thus far suffi- 

 cient, but the exact genetics, trying to find a more or less mathematical judgment of the geno- 

 type of a given individual cannot be content with this in many cases inadequate method; we 

 must try to find another, perhaps chemical method, to determine the genotype of an organism. 

 A critical and more refined judgment of methods for finding bloodrelationship, but then 

 applied to gametes, may in future lead to great results. — M. J. Sirks. 



1128. Sirks, M. J. Uit het Instituut voor veredeling van landbouwgewassen. Vergelijking 

 van gerst- en tarwerassen, van het Instituut afkomstig met andere voortreffelijke rassen van deze 

 gewassen. 1915-1917. [From the Institute for the Improvement of Agricultural plants. Com- 

 parison of barley and wheat varieties originating from the Institute with other superior races of 

 these plants. 1915-1917.] Med. Landbouwhoogeschool Wageningen 14: 1-34, 210-232. 1918. — 

 Gives only some reports of comparisons of newly bred varieties of wheat (Millioen III and Im- 

 periaal Ila) with the well-known Wilhelmina, that show the great value of these varieties of 

 wheat. The results of tests with new races of barley (Pollux and Castor) were less favorable. 

 — M. J. Sirks. 



1129. Snell, K. Farbenanderung der Kartoffelblute und Saatenanerkennung. [Color 

 changes of the potato blossom and the recognition of varieties.] Der Kartoffelbau 1919: 1-3. 

 1919. — Author calls attention to importance laid on color in recognition of varieties but a ques- 

 tionnaire proved that with many varieties color variations occur that are "spontaneous" 

 while with others they appear as non-hereditary "modifications"; these are, of course, not 

 distinguishable by inspection. Author thinks that all varieties possess power of pigment for- 

 mation and bloom white if conditions for development are absent. It is suggested that in 

 judging the variety, plants with deviations in flower color should be especially attended to 

 only when they also vary in other respects. [From anonymous review in Zeitschr. Pflanzen- 

 ziicht. 7: 137-138. Dec, 1919.]— J. P. Kelly. 



1130. Sommer, K. tiber Kartoffelziichtung und vergleichende Anbauversuche mit Neu- 

 ziichtungen auf der Domane Ellischau. [Potato breeding and comparative cultural tests of new 

 varieties on the Ellischau estate.] Nachr. Deutsch. Landw. Ges. Osterr. 1919: 190-193. 1919. 

 — Calls attention to hybridization and plant-selection work undertaken, and special mention 

 is made of large yields of single plants. [From anonymous review in Zeitschr. Pflanzensiicht. 

 7: 138. Dec, 1919.]—/. P. Kelly. 



1131. Stahel, G. Eerste verslag over de werkzaamheden ten behoeve van de selectie van 

 Koffie en Cacao. [First report on the effectiveness of selection in coffee and cacao.] Dept. 

 Landbouw. in Suriname, Paramaribo, Bull. 36. 23 -p. 1919. — Coffee and cocoa plants gener- 

 ally more or less heterozygous and efforts at vegetative multiplication of good plants are 



