January 2, 1914] 



SCIENCE 



37 



small quantities of cottonseed meal the ni- 

 trate nitrogen may begin to accumulate 

 again after ten days' incubation. With 

 larger quantities the time is longer. This 

 fact has probably caused many to overlook 

 the first disappearance. 



Just what becomes of the nitrate nitrogen, 

 under such conditions, has not been deter- 

 mined. There are two possibilities. It may 

 be liberated in the elementary form through 

 the process of denitrification. This seems im- 

 probable since the soil in the writer's experi- 

 ments has never been much over an inch in 

 depth and never more than two thirds satu- 

 rated, hence aeration was good. Another 

 possibility is that it may be assimilated. 

 There is always a very copious growth of soil 

 fungi of various forms when cottonseed meal 

 is applied. In fact, so abundant are the 

 mycelial threads that they bind the soil to- 

 gether in a mass which is rather difficult to 

 disintegrate by the ordinary shaking method. 

 It is highly probable that at least a portion 

 of the nitrate nitrogen is assimilated by this 

 growth. It would seem that it would be very 

 easy to determine the above question, but the 

 volatilization of ammonia where large 

 amounts are being formed, as is always the 

 case in the presence of cottonseed meal, makes 

 it difficult. 



It is evident, from what has just been said, 

 that deducting the nitrate nitrogen originally 

 present or that in an incubated check, will not 

 give us correct results under the conditions 

 mentioned above. The more nitrate nitrogen 

 initially present, the less reliable will be our 

 results. These two methods must then be 

 abandoned. Simply taking as the correct fac- 

 tor the amount found at the final analysis 

 will probably approach nearer the truth than 

 any other method now in practise. However, 

 we have no assurance that this gives us an ac- 

 curate idea of the relative amount formed in 

 different soils. There is absolutely no way of 

 determining the actual amount formed that 

 immediately disappears. We only know that 

 in this method the actual amount present at 

 one time (unless very large amounts were 

 initially present) was zero, and that all 



formed at any future date must have been 

 formed during the course of the experiment. 

 P. L. Gainey 

 Department op Botany, 



IjNrVERSITY OF MISSOURI 



ON THE APPARENT ABSENCE OP APOGAMY IN 

 (ENOTHERA 



In a previous note in Science^ I described 

 certain experiments which suggested that 

 (Enothera was occasionally apogamous. Three 

 imperfect seeds were obtained from a cas- 

 trated flower of 0. mut. lata, suggesting the 

 possibOity that a small percentage of the 

 seeds might develop apogamously. Last year 

 (1912) the experiments were carried out more 

 extensively, however, and the results were 

 wholly negative, showing that if apogamy 

 occurs in 0. mut. lata it must be very rare 

 indeed. 



Six lata plants were experimented upon, 

 whose history was as follows: one was a 

 mutant appearing in a culture of a race of 

 0. Lamarchiana from the Kolosvar Botanical 

 Garden; two were derived from lata self -polli- 

 nated in the cultures of de Vries; two were 

 mutants occurring in a rubinervis-YikB race ob- 

 tained from Heribert-Nilsson in Sweden; and 

 one was 0. hiennis mut. lata appearing in a 

 race of 0. hiennis from the Madrid Botanical 

 Garden. On these plants over 20 flowers were 

 castrated and covered with bags during the 

 height of the blooming season, from July 22 

 to August 13, 1912. In addition, a whole 

 branch of one pollen-sterile lata plant, contain- 

 ing 20 flowers, was covered with a large bag. 

 No growth of the capsules took place in any 

 case, and not a single seed could be found in 

 any of the capsules. It would appear, there- 

 fore, that under these circumstances at least, 

 apogamous development practically never 

 occurs in lata, for the number of ovules in the 

 capsules observed must have numbered several 

 thousands. The plants were, moreover, all 

 well nourished. 



Similar experiments made with eight flowers 

 belonging to four plants of 0. mut. gigas also 



1 Grates, E. R., ' ' Apogamy in (Enothera, ' ' Sci- 

 ence, N. S. 30: 691-694, 1909. 



