762 



SCIENCE 



[N. S. Vol. XXVII. No. 



Differentiation is the rule, and its end is 

 the death of the cell. 



Inheritance in Protozoa: Herbert Spencer 

 Jennings, of the Johns Hopkins Univer- 

 sity. 



Heredity has never been thoroughly 

 studied among the Protozoa. This paper 

 gives the results of an extensive experi- 

 mental and statistical investigation of a 

 number of generations of Paramaecium, 

 raised from cultures and from "wild" 

 forms. It has been assumed that the in- 

 heritance of acquired characters is normal 

 among protozoa, though uncommon among 

 higher forms. The author does not find 

 that inheritance of acquired characters is 

 more common in Protozoa than in Metazoa. 

 "Wild" races of large or small size breed 

 true to type, and in these the larger mate 

 with the larger and the smaller with the 

 smaller as a rule ; when different sizes mate 

 they produce different sized offspring, in 

 the few cases where the mating is fertile. 

 The production of new races does not 

 readily occur by either inheritance of 

 acquired characters, by selection or by 

 mating. 



Determination of Dominance in Mendelian 

 Inheritance: Charles B. Davenport, of 

 Cold Spring Harbor, N. Y. 

 In studying heredity, where a single 

 character is considered which one parent 

 possesses and the other lacks, or a character 

 that is contrasted in the parents, it is gen- 

 erally found that the offspring are alike, 

 and like one parent only. From examples 

 of poultry, of insects, of certain mammals, 

 including man, and certain plants in regard 

 to inheritance that may be described as 

 Mendelian, it is concluded that where a 

 stronger determiner meets a weaker de- 

 terminer in the germ, dominance is the 

 result. "When the character is present in 

 one parent only, we have the extreme case 

 and typical Mendelian inheritance, but 



when the determiners are of nearly equal 

 potency the Mendelian law is obscured. 



A Preliminary Report upon a Crystallo- 

 graphic Study of Hemoglobins: A Con- 

 tribution to the Specificity of Vital Sub- 

 stances in Different Vertebrates: Edv^akd 

 T. Reichert and Amos P. Brown, of the 

 University of Pennsylvania. 

 The primary object of this research was 

 to determine whether or not corresponding 

 albuminous substances are identical in dif- 

 ferent species. The results of the investi- 

 gation, which has covered more than one 

 hundred species of vertebrates, show: (a) 

 the crystals of oxyhemoglobin obtained 

 from any single genus are isomorphous, 

 but unlike those obtained from other gen- 

 era, unless these genera are closely related 

 or in the same family; (b) specific differ- 

 ences in angle and habit are observed be- 

 tween crystals obtained from species of the 

 same genus, so that it is generally possible 

 to recognize the species by the crystals; 

 (c) the occurrence of several types of crys- 

 tals of oxyhemoglobin occur in the same 

 species; (d) indications are found in the 

 crystal angles of a substance in the mole- 

 cule common to all hemoglobins, no matter 

 what the system of crystallization. The 

 application of this method of research to 

 problems in zoological classification and in 

 heredity was pointed out. 



The Excretory Organs of the Metazoa, a 

 Critical Review: Thomas H. Montgom- 

 ery, of the University of Texas. (Read 

 by title.) 



The Effect of Certain Preservatives upon 

 Metabolism: Harvey W. Wiley, of the 

 U. S. Department of Agriculture. 

 Details were given of the work that Dr. 

 Wiley is carrying on, in the study of the 

 effect upon the human organism of a num- 

 ber of preservatives commonly used in the 

 preparation of foods, such as borax, boric 

 acid, salicylic acid and salicylates, sulphur- 



