122 EXPERIMENTS IN CKOSS-FERTILISATION OF SALICES. 



the spines on the capilHtium observed m our English gatherings ; 

 in some the spines are scattered and longer than the diameter of 

 the thread, in others they are minute and unusually crowded. 



51. Perich^na VARIABILIS Eost. On dead wood, Antigua. Fine 

 specimens of winding and anastomosing plasmodiocarps, which vary 

 in colour from brown to olive-ochraceous ; the characteristic papil- 

 lose inner wall is well marked. 



52. Perich^na depressa Libert. Mr. Gran writes : " On fallen 

 bark, often on the inner side and seeming to love the dark"; 

 Antigua. There are four handsome gatherings, showing great 

 diversity of colour in the sporangia ; in one they are pale ochre, 

 with the outer wall strongly charged with crystalline deposits of 

 lime ; the others vary from dull rosy red to deep purple-brown ; the 

 profuse capillitium in the pale and red sporangia is remarkably firm 

 and even in thickness ; that of the purple-brown sporangia is of the 

 usual irregular and weak type ; the spores measure 9 /x. 



53. Lycogala miniatum Pers. On dead wood, Antigua. The 

 sethalia are small, with thin but characteristic cortex. 



Explanation of Plate 385. — 1. Pity sarum pallidum List. 2. Physarum 

 variabile Eex, ^ sessile. 3. Physarum Berkeleyi Kost. 4. Physarum murinum 

 List. /3 ceneum. a. Sporangia x 20. h. Capillitium and spores x 280. c. Spore 

 X 600. 



Note. — Since the foregoing went to press, I find that Dr. Raci- 

 borski has published in Hedivi/iia, xxxvii. 1898, pp. 50-55, an account 

 of the Mycetozoa he had collected in Java in 1896-7. Among the 

 species he enumerates is Physarum hogoriense Eacib., n. sp., the 

 description of which so accurately applies to the specimens of 

 P. pallidum received from Mr. Gran, that I cannot doubt it is the 

 same species; in which case P. hogoriense must take precedence as 

 its first published name under Physarum. 



EXPEEIMENTS IN GEOSS-FEETILISATION OF SALIGES. 

 By Edward F. Linton, M.A. 



It not unfrequently happens that a suspected willow-hybrid has 

 to be left in interminable doubt as to its origin, for want of con- 

 vincing evidence. Such is the case of S. decipiens Hoffm. and 

 S. acuminata Sm. ; they were described long ago ; their origin has 

 been speculated on and guessed at, with no definite result ; but if 

 either of these could be reproduced through cross-fertihsation by 

 hand, a puzzling question would be settled. 



It occurred to me some years ago to make experiments among 

 the willows growing in my garden, in the hope of obtaining hybrids 

 about whose origin there could be no doubt. This was not so easy 

 a matter as it seemed ; the process ife Hable to all sorts of mis- 

 carriages ; failures have been far more numerous than successes ; 



