DEPARTMENT OF EXPERIMENTAL EVOLUTION. 121 



of an}'^ plant decreases as the plant becomes older. A similar periodicity- 

 has been described in other species, but usually in such cases the pro- 

 portion of abnormal fruits increases with the age of the plant. The 

 interpretation of the result is still uncertain. 



Chemical and Morphological Differences, J. A. Harris and R. A. Gartner. 



Dr. Harris and Dr. Gortner have undertaken studies on chemical 

 differences associated with those of a morphological character. It ap- 

 pears that in a species {Lager stroemia indica) with dimorphic anthers, 

 the larger red anthers lose water more rapidly upon evaporation than 

 the slightly smaller yellow ones, a correlation that has a certain eco- 

 logical bearing. Attempts were made to detect a chemical difference 

 in the juices of apples and pears of varying size and fertility; the 

 conclusion reached is: 



"We have, however, been unable to demonstrate any sensible differences in 

 the osmotic pressure, mean molecular weight, or electric conductance of the 

 saps of nearly ripe fruits of different sizes or producing different numbers of 

 seeds. However, between the tissues of the normal capillary whorl consti- 

 tuting the wall of the fruit of PassiUora gracilis and those of the tetramerous, 

 abnormal whorl forming the teratological mass, i. e., the secondary fruit some- 

 times found within the otherwise normal fruit, there is unquestionably a 

 differentiation in 'physico-chemical 'properties of the expressed juices, as follows: 

 The specific gravity, specific electrical conductivity, osmotic pressure, and 

 ratio of the electrical conductivity to the depression of the freezing-point are 

 distinctly higher in the saps extracted from the tissues of the wall than in that 

 expressed from the abnormal mass. Thus the electrolytes form a relatively 

 smaller and the non-electrolytes a relatively larger proportion of the solutes in the 

 sap of the teratological tissue. Apparently the mean molecular weight of the 

 solutes of the sap of the included mass is higher than that of those extracted 

 from the wall." 



These matters are discussed in detail in a paper now ready for the 

 press. To facilitate the calculation of molecular weights and osmotic 

 pressure in saps from observed depression of the freezing-point. Doctors 

 Harris and Gortner prepared for publication two extensive tables. 



Modification of the Germ-plasm by Alcohol, G. C. Bassett. 



The problem of inducing changes in the germ-plasm has been attacked 

 by subjecting organisms to the action of alcohol vapor. This is a 

 method which Stockard has already employed Vv^ith success in demon- 

 strating that after having been subjected to the vapor of alcohol the 

 capacity of germ-cells for producing viable offspring diminished. Dr. 

 Bassett has sought to find if any inheritable effect of such alcoholization 

 of a parent upon intelligence of its offspring might be detected. Unfor- 

 tunately, after having elaborated the method with great care, he was 

 obliged to abandon the experiment. Its continuation is now in the 

 hands of Dr. MacDowell. 



