TABLES 7-11 (continued) Data pertaining to specific electrical conductivity, and to ratio of electrical con ductivity to depression of the freezing point d, of the wall. Expressed in this way the specific gravity of the sap of the prolification is from 5.50 to 11.50 percent lower than that of the wall. Turning now to concentration, we note that in only one instance does the concentration of the solutes in the sap of the prolification equal or exceed that of the ovary wall. The averages are: E 0.04224 0.04009 -0.00215 ±0.00061 ±0.00069 ±0.00091 B. SPECIFIC ELECTRICAL CONDUCTIVITY. (Data, Tables 7-11.) The electrical conductance of plant saps is in a large measure due to the presence of inorganic salts. Organic acids probably play a very minor rôle because of their low ionization constants. The mean values and the probable errors of mean values for the conductivities of the saps of the two parts of the proliferous fruit are, for the three series in which the number of determinations are numerous enough to make it worth while to calculate probable errors, given in the appended summary: Confining our attention for the moment to the mean values, we note (a) that they are of about the order of 0.1 N KC1; and (b) that they differ significantly from series to series. Thus, the difference between Series C and Series D is, for the wall, 0.003013± 0.000224; for the prolification, 0.001053 ± 0.000332. The difference between Culture D and Culture E is, for the wall, 0.001162 ±0.000217; for the prolification, 0.001440±0.000181. These differences are several times as large as their probable errors. The range of variation in observed conductance from sample to sample is indicated below: Expressing the results in terms of the standard deviation we find: Any regularity of the kind noted for the constants hitherto discussed cannot be detected. One can neither assert (a) that the tissues of the wall show more (or less) variability in the concentration of electrolytes than do those of the included mass, nor (b) that the series collected during a limited period of time show less variability than those collected over a considerable period. A glance at the tables of data shows a very consistent difference between the electrical conductance of the sap of the ovary wall and that of the abnormal mass. In no instance is the concentration of salts in the prolification as high as the concentration in the fruit wall. The absolute difference between the electrical conductivity of the sap of the wall and that of the prolification is remarkably constant. The differences between the averages are given with their probable errors in the above summary. The differences are about 20 times as large as their probable errors. Thus there is no possible question of the trustworthiness of the difference between the conductance of the sap expressed from the ovary wall and that from the included mass. The conductance of the sap from the mass is 34.7 percent, 34.6 percent, and 29.6 percent lower than that from the wall. Note that these are higher percentage differences than those obtained for the specific gravities. To this point we shall return later. C. DEPRESSION OF THE FREEZING POINT AND OSMOTIC PRES SURE. (Data, Tables 12-16.) The osmotic pressure is due to both the organic and inorganic solutes. It has been calculated from the corrected depression of the freezing point by means of the formula P = 12.0604 -0.021 Δ2. The work was facilitated by the tables which we have published elsewhere (Harris and Gortner, 1914), For purposes of the present discussion, the values of A and P may be taken as equivalent. Since most workers are more accustomed to think in terms of atmospheres-pressure, we shall tabulate values of P rather than A. |