220 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
Early Flowering. — Beurre d'Anjou, Beurre Clairgeau, Harrington's Victoria, 
Howell, Kieffer, Lawrence, Bakehouse's Bergamot, Brockworth Park, Citron 
des Carmes, Easter Beurre, Forelle, Garber's Hybrid, Le Conte, Marechal de la 
Cour, Monchallard, Poire de Berriays, St. Michael Archangel. 
Intermediate Flowering. — Beurre de Capiaumont, Black Achan, Clapp's 
Favourite, Doyenne Boussock, Doyenne du Cornice, Durondeau, Gansell's 
Bergamot, Glou Morceau, Josephine de Marines, Madame Cole, Packham's 
Triumph, Souvenir du Congres, Vicar of Winkfield, Winter Cole, Winter Nelis ; 
Beurre Giffard, Beurre Diel, Beurre Hardy, Brown Beurre, Brown Windsor, 
Catillac, Cole's Hybrid, Elizabeth Cole, Fertility, Flemish Beauty, Golden 
Beurre, Idaho, Jargonelle, Urbaniste, Lady Lynn, LTnconnue, Louise Bonne 
of Jersey, Mount Vernon, Napoleon, Neverfail, Pitmaston Duchess, Summer 
Bon Chretien, Swan's Orange, Uvedale's St. Germain. 
Late Flowering. — 'Beurre Bosc, Broompark, Marie Louise, Williams' Bon 
Chretien, Autumn Bergamot, Bailey's Bergamot, Beurre Bosc, Laffer's 
Bergamot. 
The average time the different varieties were in blossom was found to be 
twelve to eighteen days, and, from first flowers to full bloom, six to twelve 
days.— C. H. H. 
Pear Tree Stock. By E. Wallis in " Pear-Growing in Victoria " {Jour. Dep. 
Agr., Vict. Nov. 191 9, p. 660). — To avoid stock which suckers, it is recom- 
mended to select seed from the Oriental type of pear, such as Kieffer, a hybrid 
of the Chinese Sand pear, which produces seedlings of thrifty growth and clean 
stem. Broompark also produces a good stock, but Kieffer seedlings are generally 
the most suitable.' — C. H. H. 
Pears and Apples, Ripening of, as Modified by Extreme Temperatures. By E. L. 
Overholser and R. H. Taylor (Bot. Gaz. lxix. No. 4, April 1920, pp. 273-296). — 
The following summary of results is given : — 
1. When contrasted with temperatures between 70 and 85 0 F., temperatures 
of 87-7 to no° F. caused an appreciable dekiy in the ripening of green first- 
crop Bartlett pears. 
2. The retardation of ripening was directly proportional to the increased 
degree of heat within the limits of 87 0 and 104 0 F. 
3. The amount of delay in ripening of green first-crop Bartlett pears of the 
different temperatures when contrasted with 70 0 F., or room temperature, was 
as follows : 85 0 F., no retardation ; 87' 7 0 F., 5 days ; 94 0 and 104 0 F., 13 days. 
4. Second-crop Bartlett pears, placed at a temperature of 101 0 F. and sur- 
rounded by a relative humidity of below 50 per cent., remained unripe 4 weeks 
after similar pears had become fully ripe at room temperature and humidity. 
5. The relative humidity does not seem to be a significant factor in checking 
the ripening processes. Its effect is in lessening or permitting wilting, depending 
upon whether the relative humidity surrounding the fruit is high or low. 
6. The flavour of the pears subjected to those temperatures higher than 
85 0 F. was not normal. There was a slight acidity, and the sweetish taste and 
juiciness were lacking. 
7. Temperatures above no 0 F. result in a more rapid ripening and conse- 
quent breakdown of the tissue than do any of the lower temperatures, down to 
average room temperatures. 
8. As would be expected, there was a comparatively large loss from rot 
with the fruit kept at high temperatures and surrounded by high relative humidity. 
9. A possible explanation of the effects of high temperatures may lie in the 
influence upon the enzymes. Temperatures approaching the probable minimum 
(around 28 0 F.) on the one hand, and the probable maximum (around no° F.) 
on the other, might result in a reduction of enzymatic activities of the fruit, 
and a consequent retardation of the ripening processes ; while with the optimum 
temperatures (70-85 0 F.) the enzymatic activity would be most marked, and 
hence the ripening most rapid. 
10. If the Bartlett pears have nearly reached a stage of complete ripeness, 
the temperatures above 70 0 F. do not check the ripening process. On the other 
hand, the ripening and breakdown are more rapid with each appreciable rise 
in temperature. 
11. Unripe Easter pears behave in a manner comparable to the Bartlett 
when placed under similar conditions of high temperature and relative humidity. 
12. The process of ripening with yellow Newtown apples is not delayed by 
temperatures above 32 0 F. The ripening takes place with increased rapidity 
with each appreciable rise in temperature above 32 0 F. This is true with tem- 
peratures up to a point which result in the disorganization of the protoplasmic 
contents of the cells. 
