668 EXPERIMENT STATION RECORD. 



to some extent they difl not exhibit nearly as many S]iots as the unprotected por- 

 tions of the tree. It is beheved that the infection was caused through the develop- 

 ment of the sporidia of the fungus and not directly through the distriljution of the 

 teleutosi)ores. Laboratory experiments were conducted with the teleutospores, in 

 which it was found that the best germination took place on slides wliich were 

 moistened and placed in the sunlight under bell jars. This allowed the spores to 

 dry slowly, thus affording natural conditions for sporidia production. The galls pro- 

 duced on the cedar are believed to be perennial. The mycelium passing the summer 

 in the old gall produces new outgrowths and a second crop of spores in the following 

 spring. In this way the occurrence of the Rcestelia stage of the disease in 1901, fol- 

 lowing an almost total disappearance of the cedar apples, may be explained. Marked 

 differences are reported on the immunity of different varieties of apples as observed 

 in the different orchards. 



Pink rot, an attendant of apple scab, J. Cr.^ig and J. M. Van Hook {New 

 Yoi'k Cornell. Sta. Bui. 207, pp. 161-171, pis. 2, figs. 5). — Attention is called to a very 

 destructive rot which accompanies and follows apple scab. This is caused by a para- 

 site which appears only on apples infested with scab. It is first noticed as a thin 

 gray mildew, always thicker around the margin of the scab s])ots. Later it assumes 

 a pink color, due to the maturing of the fungus. The apple scab fungus as it 

 matures ruptures the skin of the apple and the edges are left somewhat upturned, 

 and it is through these broken surfaces that the pink fungus gains entrance. The 

 first appearance on the apples is the browning of the e})idermis about the scab spots. 

 This gradually extends in all directions, imtil by the merging of the spots large areas 

 or the entire surface may be involved. As the spots increase in size the surface 

 l)ecomes sunken by the dissolution of the solid parts of the apple underneath, as 

 well as the evaporation of water thi-ough the spots. The fungus, which has been 

 identified as Cephalothecium roseum, is not ordinarily considered as a parasite, but 

 usually grows upon decaying vegetable mattei". The atmospheric conditions for 

 spraying were very unfavorable during this season, and as a consequence there was 

 an unusual development of apple scab. The injury caused by the scab made pos- 

 sible the al>undant development of the pink fungus. Good tillage, careful pruning 

 and spraying, which will result in the production of apples free from scab, wouM 

 also prevent the occurrence of this pink rot. Experiments were carried on to test 

 the practicability of disinfecting apples by dipping or fumigating them to prevent 

 the growth of this fungus. Samples were dipped in solutions of copper sulphate 

 and formalin and were fumigated with formaldehyde gas and with vapors of sul- 

 phur, the best results being obtained where the formaldehyde gas was used. Storing 

 the apples at low temperature will retard the development of the pink rot, but it 

 is probable that removing fruit from cold storage would increase the rapidity of the 

 decay. 



The bitter rot of apples, H. von Schrenk and P. Spaulding {Science, n. ser., 

 16 {190:^), No. 408, 2)p. 069, 670). — A description is given of recent investigations on 

 the origin and distribution of the bitter rot of apples, a note on which has been 

 given elsewhere (E. S. R., 14, p. 367). It is claimed that the bitter rot can be traced 

 to canker spots on the limbs of the apple tree. Spores from apples inoculated into 

 living apple branches produced the canker, and healthy apples reinoculated from 

 the canker produced the bitter-rot disease on the fruit. Inoculations of pure 

 cultures gave similar results, and it appears that there is a causal relation between 

 apple cankers found in the orchard and the bitter-rot disease. It is considered prob- 

 able that the fungus Ghi'osporiumfrnctigenum'is capable of living l)oth in the bark 

 and fruit of the api)le. This fact is imjxirtant in assisting apple growers to combat 

 the disease. 



Brown rot of stone fruits, F. T. Bioletti {('allforniu Sla. Ei>t. 1S99-1901, pt. 2, 

 jiji. 3S0-S33, fig. 1). — The brown rot of stone fruits caused by Monilia fructigena has 



