1890.] 



occurring in the NeiglihonrJwod of Siuila. 



103 



size mensnres yV*'^ ^^^^ ^^^ length and ^^oth. to ^^^^h inch in depth. 

 The uumher of these borne on one needle is usually about four ; but varies 

 from one to six, and in exceptional instances even more may be found. 



The mycelium is confined to the paled portions of the needles and 

 is therefore strictly localised as in the above species. The hyphae 

 ramify among the parenchyma cells betvv^een the hypoderma and the 

 endothelial sheath, and does not penetrate within the latter. There are 

 no haustoria. 



The peridium is very tough and white, consisting of two layers of 

 cells firmly adherent to one another, as in the case of the above species ; 

 but the peridial cells are much larger, measuring about 4-0 x 22/x or 

 42 X 21/x (figs. 6, 7, PL III). This difference is so great as to justify 

 me, I think, in regarding it as a distinct species. 



The aecidiospores are oval and oiange red, with a stout ej^ispore 

 beset with prominent spines. The epispore is often thickened more on 

 one side than on the other (fig. 2, PI. III). They are formed in long 

 serial rows, and in great numbers within each peridium. Between the 

 lower ones intercalary lamellae are present. The dry spores measure on 

 an average 27'5 x 16'9/x and when moistened, 27"3 x 193/x. After 

 lying 24 hours in water they measure 30'2 x 21 2/x on an average. I 

 have failed to observe the germination of these spores also in cultiva- 

 tions, although I have tried them in various media. 



Spermogonia. These are of the usual structure ; but are very large 

 and deeply set. 



Remarks. — I think the differences between these two Aecidia are 

 sufficient to warrant their separation as two distinct species. With a 

 view to ascertaining the exact difference in the size of the aecidospores 

 and the peridial cells of the two species I simultaneously treated both 

 in the same way, and then carefully measured them. The needles bear- 

 ing aecidia were first placed in a mixture of equal parts of glycerine 

 and alcohol and then examined in pure glycerine. The aecidiospores 

 from P. longifolia measured on an average of several individual measure- 

 ments 22 8 X 15/x, whilst those from P. excelsa measured 28'6 x 18'4/x. 

 The differences between the aecidiospores and the peridial cells are 

 shown in the following table : 





Aecidiospores. 



Peeidial cells. 



Host. 



Moistened 



in 



water. 



Dry. 



24 hours 



in 



water. 



Alcohol 



and 



glycerine. 



Alcohol 



and 



glycerine. 



Water. 



P. excelsa ... 

 P. longifolia 



27 3 X 19 3 

 25-4 X 17 9 



27 5 X 169 

 24-3 X 17-9 



30-2 X 21 2 

 26-4 X 19 6 



286 X 18-4 

 22-3 X 15-0 



40 X 22 

 27-6 X 17-2 



129 5 X 91-5 

 38 X 41-3 



