摘要:

The behavior of different types of apple crosses was found to be very similar, whether or not emasculation was practiced, indicating that selfing was not a serious factor in the latter case. In both cases it was found that (1) all varieties were fruitful when diploid varieties were used as male parents, though triploid × triploid crosses sometimes approximated the latter in this respect, and that (2) all varieties, regardless of chromosome constitution, were less fruitful when triploids were used as male parents. Though triploid varieties had a lower seed content than diploids, the seed content within the variety was characteristically greater wherever diploids were used as pollen parents. The results obtained with respect to seedlings were in general agreement with those based on seed alone, the order of production being as follows: first, diploid × diploid; second, triploid × diploid; third, diploid × triploid; and fourth, triploid × triploid. No correlation between seed content and weight could be demonstrated in Gravenstein, Baldwin, King and Wagener and a barely significant correlation in the case of Northern Spy. Various morphological abnormalities resulting from imperfect pollination are described.

ISSN:1923-4287    

DOI:10.1139/cjr33-088

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

The chief purpose of the investigations described in this paper was to determine the relative pollen constancy of the various insect pollinators of the apple. In addition to the hive bee, these proved to be solitary bees belonging to the generaHalictusandAndrena, with Bremidae and various Diptera playing a minor role. It is pointed out that apparent flower constancy depends a great deal upon availability and that almost any result may be obtained by choosing certain periods in which to make tests. The results, based on analyses of the pollen loads of bees captured in apple blossoms, place the hive bee first as regards the number of pure loads, followed byHalictus, withAndrenaa poor third. Taking into consideration the results of the entire season, and the analyses of bees from different sources of pollen,Halictuscame first in these particular tests, but the difference is not considered significant. The supposed superiority of the hive bee from the standpoint of constancy does not appear to have been proved. BothHalictusand the hive bee, however, evidenced a significant superiority over theAndrenaspecies studied.

ISSN:1923-4287    

DOI:10.1139/cjr33-089

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

In this paper it is shown that by plating cultures ofCl. welchii, on a suitable hormone-blood agar, two distinct colony types, regarded as S and R, and frequently intermediate types, may be isolated. Once isolated and stabilized by continued cultivation and selection at least the two more extreme types show true breeding properties. Serial cultivation in various fluid media, particularly Robertson's chopped meat, has resulted in both S to R and R to S variation. This has been observed in strains purified by colony selection and by single cell isolation.The S type has proved to be highly virulent for pigeons, the R type much less virulent but there is some evidence that the apparent killing action of R types may result fromin vivodissociation of the R to S. Both S and R types are shown to yield hemotoxin which is neutralized by antitoxin but under similar conditions S types produce 10 to 20 times more toxin than R types.

ISSN:1923-4287    

DOI:10.1139/cjr33-090

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

Studies have been made on the decomposition of creatine in acid and alkaline solutions at 37.5° and 50 °C. The rates of transformation to creatinine in acid solutions gave values for the Arrhenius constant varying from 20,700 to 24,000, values in moderate agreement with those of Edgar and Wakefield.There was a definite minimal rate of transformation at approximately 0.1Nhydrochloric acid, and a secondary maximum at about 0.01Nhydrochloric acid. This was probably owing to catalysis of creatine hydrochloride and free creatine at different rates. The slightly differing values found for the Arrhenius constant in strong and in weak acid solutions may be explicable on this basis.The results with alkali support Gaebler's views that creatine is initially transformed into urea and sarcosine, which then reunite to form ammonia and methyl hydantoic acid.These results show further that in solutions of acid and alkali of corresponding strength, alkali catalyses the change from creatine to creatinine much more rapidly than acid.

ISSN:1923-4287    

DOI:10.1139/cjr33-091

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

A study has been made of the influence of various electrolytes in promoting gelation of aqueous supersaturated solutions of the urates of methylamine, lithium, piperazine and tetramethylammonium. The cation has been found to be the active agent. The minimal concentration of the electrolyte which is effective has been determined over the gelation range of the urate. The order of efficacy of the cations may be stated in general to be K > NH4> Rb > Cs > Li > Na. A maximal concentration of electrolyte has been found above which immediate precipitation rather than gelation occurs. The time required for gelation varies inversely with the amount of electrolyte present in any single concentration of urate. The rigidity varies directly up to the point of precipitation. The time of crystallization of the gel variesdirectlywith the concentration of the electrolytes, sodium chloride, rubidium chloride and lithium chloride butinverselywith potassium chloride and ammonium chloride. Certain organic diamines have been found to possess the power of causing gelation over a limited range of urate. Ethyl alcohol, between 20 and 60%, causes gelation of lithium urate and methylamine urate.The thixotropic effect has been observed in gels of piperazine urate containing potassium chloride and lithium urate with alcohol.The action of electrolytes on urate gels is interpreted as partially electro-kinetic and partially lyotropic in nature.

ISSN:1923-4287    

DOI:10.1139/cjr33-092

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

The base-exchange properties and the constituent materials of the base-exchange complexes of Quebec Appalachian upland podsol soils have been studied. It has been shown that the "availability" of the acid semihumified organic matter has played the most important part in bringing about existing conditions in these soils. Organic matter is dominating the processes through which these podsol soils pass in their progress from a slightly leached to a severely leached condition. The inorganic base-exchange complexes are superseded by organic complexes. The more "available" iron and aluminium present in these soils the less is their base-exchange capacity. The inorganic base-exchange complexes are unstable under the strongly acidic soil conditions. The restoration of fertility to these soils must be approached through modification of their organic-matter conditions.

ISSN:1923-4287    

DOI:10.1139/cjr33-093

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

The density of monomeric vinyl acetate has been determined over a range of temperature. The parachor and Ramsay and Shield's constant have been obtained for the monomer and some liquid polymers. On the assumption that a liquid polymer may be considered as a solution of a dimer in the monomer, parachors were calculated from the mixture law.If Staudinger's formula be assumed for the dimer the calculated and observed parachors agree to within 1%.

ISSN:1923-4287    

DOI:10.1139/cjr33-094

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

An experimental determination of probability is described in this paper. Steel balls were dropped on to a horizontal plate pierced with holes in regular array, and the number which passed through without contact with the plate was observed. The ratio of the number of free passages to the total number of balls dropped is the experimental probability, and this number was found to be in very close agreement with the probability calculated from measurement of the balls and holes. Since this calculated probability involves π, the experimental probability may be used to calculate π which was found to be 3.143 ±.005. The paper closes with a brief discussion of the application of probability to certain problems in physics.

ISSN:1923-4287    

DOI:10.1139/cjr33-095

出版商:NRC Research Press    

年代:1933

数据来源: NRC