MiCROSPHAERA 153 



(7 fi wide), more or less rigid appendages of M. aim. Certain 

 specimens, however, especially some on Qiiercus alba, show all in- 

 termediate stages between JSL alni^ and the var. cxtcnsa, and in 

 these it is clearly seen that as the appendages become shorter they 



/ 



nary 



M, alni as it occurs on oaks. The specimens in Ellis' N. 

 Amen Fungi, no. 429, show such intermediate stages between JZ 

 alni and the var. extensa. 



Hosts. — Qiierciis aqitatica, Q, laurifolia^ Q, nigra. 

 Distribution. — North America : United States — South Caro- 

 lina, Alabama, Florida. 



The peculiar variation of growth shown in the axial elongation 



,. .,. * 



of the apex of the appendages constitutes a striking character at 

 first sight (see Figs. 15-17), and one which might, if constant, be 

 considered of specific value. 



The character, however, is certainly not invariable. On the 

 perithecia of specimens belonging to the var. calocladopJiora^ we 

 quite commonly find single appendages which show the same regu- 

 larly dichotomous apical branching as that found in the forms of 

 M, alni on American oaks. 



On the other hand, in certain specimens of otherwise typical 

 M. alni^ we find a single appendage here and there showing the 

 axial elongation characteristic of the var. calocladopJiora. As an 

 instance of this maybe mentioned the specimens in the Herbarium 

 at the British Museum (South Kensington) labelled '' M, extensa^ 

 on fallen leaves of water oak. Quercus aqnatica^ Aiken, South 

 Carolina. H. W, Ravenel, Nov., 18S1,'' and '' M. pulchra'' on 

 Corntis alternifolia. In both these specimens, among perithecia 

 with appendages normal for M. alni, there occurs rarely a single 

 appendage with the apex formed as in the var. calocladopJiora. 



In the face of these connecting links on both sides, it is impossi- 

 ble to consider the present plant as specifically distinct. Under- 

 wood and Earle (371, p. 178) have some interesting remarks on 

 this point. 



Var. calocladopliora (Atkins.) [Figs. 15-17] 



M. densissiuia Ell. & Mart. Journ. Myc. I : loi. 1885 ; Sacc. 

 SylL Fung. Addit. ad. Vols. I.-IV.: 2. 1886 and 9 : ^6^. 1891. 



