36 GENETICS BoT. Absts., Vol. VII, 



in two large volumes, is designated as complementary alid supplementary to the author's (and 

 Brown's) well-known earlier crystallographic studies of the hemoglobins, and to his work 

 on the stereochemistry of protoplasmic processes and products as displayed through the 

 differentiation and specificity of starches (Nos. 116 and 173, respectively, of the Carnegie 

 Institution of Washington) . Like its predecessors the present study is regarded as exploratory 

 in character. The main thesis of the three sets of studies is that "in different organisms 

 corresponding complex organic substances that constitute the supreme structural compo- 

 nents of protoplasm and the major synthetic products of protoplasmic activity are not in 

 any case absolutely identical in chemical constitution, and that each such substance may 

 exist in countless modifications, each modification being characteristic of the form of proto- 

 plasm, the organ, the individual, the sex, the species, and the genus." — Since the molecule of 

 such a protein as serum-albumin may have as many as 1000 million stereo-isomers, the incon- 

 ceivable number of possible constitutional differences in the corresponding proteins of differ- 

 ent individuals is obvious. The author believes that the collective evidence available today 

 indicates that every individual is a chemical entity that differs in characteristic particulars 

 from every other, and that differences in chemical constitution and composition can account 

 for all the differences which serve to characterize genera, species, and individuals. Being 

 an inert, non-living synthetic product of metabolic activity which beavs no resemblance 

 to the protoplasm that gives rise to it, starch may be used as an indicator in determining 

 whether the products of synthesis are correspondingly modified with the stereochemical pecu- 

 liarities of the protoplasm by which they are produced. Rei chert finds that such is the case. 

 Moreover, since such differences are diagnostic, they constitute "a strictly scientific basis for 

 the classification of plants." The present research treats mainly of the properties of parent- 

 stocks and hybrid-stocks, and correspondingly, of heredity. The author thinks that the 

 importance of hybridization in the genesis of species has been greatly underrated. He ex- 

 presses the object of his research as follows: "In both of the preceding researches satisfactory 

 evidence was recorded to justify the conclusion that complex organic substances exist in 

 different stereo-isomeric forms in different organisms, and that the differences are specific 

 in relation to genera, species, and varieties, and in general in striking accord with the accepted 

 data of the systematist. Naturally it seemed to be a matter of the greatest fundamental 

 importance to determine to what recognizable degrees these physico-chemical properties are 

 transmitted from seed and pollen parents in altered or unaltered form in the hybrid; if it is 

 possible to predict the heritability of this or that property: whether or not new physico- 

 chen^iical properties appear in the hybrid; and if the phenomena of physico-chemical inherit- 

 ance are not only cons stent with, but also in explanation of, the data of the systematist and 

 with the experience of the plant breeder." In connection with a discussion of the criteria of 

 hybrids and mutants he translates a lecture of Fockb (1881) rarely found in libraries, which 

 summarizes under five propositions a great amount of data pertaining to hybrids and their 

 offspring. Reichert regards Mendelism as of value merely in explaining certain phenomena 

 of inheritance and but one of several types of mechanisms of heredity. He uses the term 

 "unit-character" and "unit-character phase" repeatedly but apparently not in the accepted 

 Mendelian sense, for he says: "The term character is used throughout this research in a con- 

 ventional sense to signify any property that serves to characterize any part or property of 

 starch or plant. Inasmuch as each such property is a unit of comparison, each may appro- 

 priately and advantageously be referred to as a unit-character." What he finds regarding 

 starch characters in hybrids when compared with those of parents may be summarized in his 

 own words: "If starch characters are heritable they should, in order to meet theoretic require- 

 ments, exhibit peculiarities of inheritance corresponding to those observed in gross and 

 microscopic anatomic plant characters. This deduction will be found to have ample justi- 

 fication in the results of this research. Herein it will be found that the starches of the 

 hybrids frequently exhibit in histologic, polariscopic, and physico-chemic properties some 

 degree of intermediateness between the parents, usually nearer one or the other. In any 

 given hybrid certain of the propert'es may be exactly or practically exactly intermediate 

 and other properties may be identical with the corresponding properties of one or the other 

 parent. In many instances one or more of the characters of the hybrid, such as the relative 



