Febeuary 7, 1908] 



SCIENCE 



209 



so that the more striking differences be- 

 tween granite hills, lateral valley and rock 

 ridges could be seen. 



A Preliminary Account of Studies in the 



Variability of a Unit Character in CEno- 



thera: R. R. Gates. 



The most striking character distinguish- 

 ing the mutant 0. rxibrinervis from its 

 parent 0. Lamarchiana, is the conspicuous 

 red color present on the petioles and mid 

 veins of the leaves and on the sepals and 

 young fruits of the former. The vari- 

 ability of this red color pattern in the 

 sepals of 0. rubrinervis has been the main 

 object of study. Painted types of indi- 

 vidual buds were used as standards of 

 classes in cataloguing the variability. The 

 variation in the extent of the red on the 

 sepals is definite, forming a reduction 

 series, the color receding from the margin 

 of the sepals and in extreme reduction ap- 

 pearing only as a series of spots along the 

 sides of the median ridge of each sepal, or 

 rarely being wholly absent. By examina- 

 tion of all the flowers of a plant, the mode 

 of the individual may be obtained, and this 

 is found to vary in different individuals. 

 One extreme variant in a culture of 1,000 

 0. rubrinervis plants showed a great in- 

 crease of the red pigment, which covered 

 not only the whole sepal (including the 

 median ridge, which is otherwise always 

 gTcen) but also the hypanthium. Whether 

 this extreme form will breed true, and 

 how it will behave in a cross, is to be de- 

 termined later. 



The buds of QSnothera Lamarchiana, 

 when attacked by a certain insect, produce 

 red pigment as in 0. rubrinervis, showing 

 that the capacity for pigment production 

 under certain circumstances is present in 

 0. Lamarchiana and not that it is con- 

 fined to certain germ cells only in which 

 it originates suddenly as a new or addi- 

 tional unit character. These and other 



facts of variation are not in accord with 

 the DeVriesian conception of unit char- 

 acters in mutation, but may be better ex- 

 plained on another basis. 



In all, 1,460 buds from 104 individuals 

 were examined in this preliminary study. 

 A more extensive study of color varia- 

 tions in (Enothera is to be made. 



Mine Fungi: Pbrlet Spaxjlding. (Read 

 by title.) 



The Loco Investigation: C. Dwight Maesh. 

 (Publication reserved.) 



Crystal Formation in Cultures of PenicU- 

 lium: Arthur W. Dox. (Presented by 

 Charles Thom.) 



In cultures of different species of Peni- 

 cillium upon Cohn's medium, the forma- 

 tion of peculiar crystals was noticed. 

 Crystals were formed only by those organ- 

 isms which gradually changed the reaction 

 of the medium from acid to alkaline. 

 Chemical analysis showed them to be mag- 

 nesium ammonium phosphate with six 

 molecules of water. This substance has 

 heretofore been obtained only by precipi- 

 tation and in microscopic crystals, whereas 

 the crystals formed in Cohn's solution were 

 often two centimeters in length. The 

 finest crystals were obtained when the cul- 

 ture was carefully maintained at a uni- 

 form temperature. This work suggests a 

 possible application of mold cultures to the 

 formation of other substances in crystals, 

 particularly those substances that are 

 soluble in acid but insoluble in neutral solu- 

 tions. 



Embryo-sac Development and Embryology 

 of Symplocar-pus fcetidtis: C. 0. Rosen- 



DAHL. 



The inflorescences of Symplocarpus 

 foetidus are borne as lateral branches in 

 the axils of the leaves on the upright, 

 monopodial rhizome. They develop very 

 slowly and the rudiments of the flowers are 



