354 IvErOKT OF THE HORTICULTURIST OF THE 



limbs made a greater growth when inoculated into pear trees than 

 the cultures did that were made from diseased pear trees. 



Various other inoculations were made that are not given in the 

 table, the details of which need not be entered into here; it may 

 be said, however, that of something over 1,000 inoculations made 

 in 1899 very few gave negative results. Eig. 1 of Plate V 

 shows an apjjle tree whose top is dead, the result of inoculations 

 made with cultures of S'phaeropsis obtained from sumach. It 

 should be pointed out, however, that this particular branch was 

 making a feeble growth, and that inoculations made in two of the 

 side branches failed to grow^ In several other instances where 

 inoculation^ were made in weak trees the fungus made a much 

 greater growth than it did in adjacent vigorous trees. This point 

 is of great practical importance and confirms what has been said 

 on this subject on a former page. Fig. 2 of Plate XXXII shows a 

 twig bliglit of pear and apple trees respectively, the result of in- 

 oculations made wdfrh cultures of Sphaeropsis from cankered apple 

 tree limbs in tAvigs of the current season's growth. 



The results of the inoculation experiments tend to show that 

 the number of species of Sphaeropsis can be materially reduced. 

 In some instances it appears that a new" host has served as a basis 

 for making a species, and since many of the hosts given in the 

 table represent different species it would sccni that this plan had 

 been followed ^vhen some of these species were made. So far 

 as the writer can determine there is but sliiiiit difference in the 

 morphological characters of the species that are represented in the 

 tables by the different hosts, such as might occur with any fungus 

 when grown on different media or when transferred from one 

 plant to another. Neither do the published descriptions of these 

 species suggest any material differences. 



A set of the Spliaeropses on the different hosts was submitted to 

 Mr. J. V>. Ellis, Newfield, i^. J., for identification with the pub- 

 lished descriptions. His determination of the species so far as 

 he was able from the specimens sent are given in Table III. 



