December 17, 1915] 



SCIENCE 



879 



the buds of secondary flowers. The latter in turn 

 bud out Tertiary ones and these initiate flowers 

 of a fourth generation, by the middle of July. 

 All of the four, or more, generations of flowers 

 formed in a season, remain attached and growing 

 for several seasons. In each succeeding season 

 any fruit of the first season 's series may give rise 

 to a similar set of primary, secondary,' Tertiary 

 and Quaternary fruits. In this way clusters of a 

 hundred fruits, including from ten to fifteen gen- 

 erations, may be formed. 



If these persistent fruits remain attached they 

 give rise only to fiower buds. If they are broken 

 ofE and placed on moist soil the same areolae de- 

 velop roots and vegetative shoots, and so start a 

 new plant. 



Teratology and Pliylogeny in the Genus Trillium: 



E. E. Gates, University of London. 



Trillium is a genus of plants which is in an un- 

 stable or mutable condition. Many of its varia- 

 tions are teratological. There are frequent rec- 

 ords of double flowers appearing, especially in 

 T. grandiflorum. In such eases it appears that the 

 same root-stock continues to produce a double 

 flower year after year. Hence a germinal change 

 must have occurred leading to the production of 

 such a rootstock. 



A form related to T. grandiflorum and known as 

 var. variegatum has been studied in Michigan, the 

 Niagara peninsula and near Syracuse, N. T. 

 This is exceedingly variable, producing in some 

 cases 10 per cent, of abnormal plants which can 

 not reproduce from seed yet which reappear in 

 large numbers each year. This form frequently 

 has long petioles to the leaves, which suggests 

 that T. petiolatum, an unrelated species with 

 long petioles, may have originated similarly 

 through a mutation. 



In various species of Trillium individuals oc- 

 casionally appear having a whorl of four leaves 

 and their flower parts in 4's instead of in 3's. 

 This is a generic feature of the related Euro- 

 Asian genus Paris. Another peculiarity of Paris 

 is the elongated connectives, a feature which is a 

 specific character in T. deoumbens and occasionally 

 appears in teratological specimens of Trillium. 



Such facts show that variations tend to follow 

 certain paths or lines of cleavage, and these lines 

 must depend upon the structure of the germ 

 plasm. It would appear that the teratological 

 variations of one genus may, under certain condi- 

 tions, give rise to the stable condition of a derived 

 genus. The paths of variation in a genus may 

 thus indicate tendencies which have found ex- 

 pression in various related genera. 



Morphology, Selationship and Sex-determination 

 in Thalocarpus curtisii: T. McAllister, Uni- 

 versity of Texas. 



The morphology of Thallocarpus Curtisii is the 

 same as that of the Riccias with two minor excep- 

 tions. The rhizoids lack the peg-like thickenings 

 characteristic of the Marchantiales, and the four 

 spores of the tetrad adhere to form a spore ball 

 as is the case with some of the Sphwrocarpus 

 species. The gametophyte seems to be the same 

 in structure as the spongy Eiccias. The sporo- 

 phyte has no traces of a foot nor of sterile nutri- 

 tive or elater-like cells. It is difficult to see how 

 this liverwort was ever included with the Sphcero- 

 carpos forms. 



The four spores of the tetrad form, on germina- 

 tion, two male and two female plants. In this re- 

 spect there is a similarity to Sphcerooarpus Texanus 

 and S. Californicus. 



Quasi-experimental Formation of Mcidia in Cot- 

 ton Leaves: F. E. Lloyd, MoGill University. 

 (Eead by title only.) 



Small plants of cotton were grown in 3-inch 

 pots for over one year, and subjected to severe 

 physiological drought, moderated sufficiently to 

 keep them alive. Plentiful watering, aided by 

 rising temperatures, resulted in forcing growth in 

 many lateral shoots, and these produced a large 

 proportion of abnormally shaped leaves. The 

 whole series presented a variety of shapes, the 

 simplest showing a mere constriction across one 

 or more lobes. Foldings, lobulations and con- 

 crescences entered in to accentuate the departure 

 from the normal, which, passing through stages 

 with ill-formed and only partially separated as- 

 cidia, culminated in perfect ascidia raised on their 

 proper petioloid supports. 



Such abnormalities appear to rise from identical 



conditions with fasciations and indeed both these 



kinds of aberrancy are found associated in the 



same plant (Fraxinus, Spinacea). They have 



been shown to be inherited in some cases. 



Desiccation and Starvation of a Succulent: D. T. 



MacDougal, E. E. Long, J. G. Brown, Dept. 



Bot. Eesearch, Carnegie Inst, of Wash. (Eead 



by title only.) 



A number of large sound individuals of Echino- 

 cactus, and of several joints of Opuntia were de- 

 prived of water supply, and compelled to carry on 

 existence at the expense of accumulated water and 

 food-material. Some of the preparations were 

 exposed to the fuU illumination to which they were 

 accustomed, and others were placed in diffuse 

 light obtaining differential effects in water-loss, 

 respiration, disintegration of acids, and photo- 



