io6 



SCIENCE-GOSSIF. 



subsequent dispersal of the spores. Even when 

 found on \\\m\g bog moss they have passed the 

 Plasmodium oi^ feeding stage on the lower and 

 decayed portions of these plants. 



Until the spring of 1897 the researches of British 

 observers were limited almost entirely to rotten 

 wood and decayed leaves, but from that period till 

 now considerable attention has been paid to the 

 possibilities of straw-heaps, especially those that 

 have lain undistm-bed for several months. These 

 . are easily recognised by the appearance of the 

 surface, which resembles old thatch. The results 

 of these investigations have been most gratify- 

 ing to those who have pursued them, for up 

 to the autumn of 1899 they have yielded 

 the previously undescribed species :—Plttjsarum 

 straminipes List.; Didymium Troelins List.; 

 the first known European record of Fuligo 



Badhamia utricularis. Fruitixg stage ox decayed wood. 

 (Plwtog-aphed from Nature.) 



ellipsogpora List. ; and the iirst known British 

 records of Badhamia ovispora Kacib. ; P7ii/sarum 

 didermoides Rost., variety lividum, var. nov. Lister 

 (the latter being recorded in the " Journal of 

 Botany," vol. xxxvi. p. 161). Extended and frequent 

 observations of the denizens of straw-heaps suggest 

 another peculiarity in their occm-rence, which is 

 that certain species affect different strata of the 

 accumulated material. In illustration or confirma- . 

 tion of this suggestion the following data are 

 advanced. The species usually found at or near 

 the surface are Thysarum caUdris List. ; P. dider- , 

 moides Rost. ; P. didermoides, var. lividum List. ; 

 Fuligo septiea Gmel. ; Didymium nigripes Fr. ; 

 Spumaria alba DC. ; Badhamia ovispora Racib. ; 

 Physarum compressum Alb. and Schw. ; P. stramini- 

 pes List. ; P. erateriachea List. ; Craterium pedun- 

 cxdatum Trent. ; C. leucocephalum Ditm. ; C. mutahile 

 . Fr. ; Chondriodcrma S2}umaroides Rost. ; C. michelii 

 Rost. ; and Periehoena variabilis Rost. 



Species usually found hi straw-heaps at or below 

 the line of saturation are Didymium difforme Duby., 

 and D. Trochns List. 



In regard to D. Trochus List., it is remarkable 

 that it rarely fruits in any other situation than 

 where the material is saturated with moisture. 

 We have had under observation during the last 

 three seasons many thousands of the sporangia of 

 this species, and it is most rare to find any of 

 them near the surface, or in such situations as 

 would favour the dispersal of the spores. They 

 ai;e usually so charged with moisture that it is 

 expedient to lift out the lower layers of straw and 



spread them out to the wind, when the sporangia 

 rapidly dry and are thus rendered conspicuous. 

 Notwithstanding these apparent obstacles to the 

 distribution of the spores, recent observations show 

 that this species is of frequent occurrence in the 

 South Midlands over an area of at least eight miles 

 square. It has also been observed near Reigate by Mr. 

 E. S. Salmon. Considering the extreme abundance 

 of this species, especially in the year 1899, the 

 question naturally arises as to where it existed 

 previous to the spring of 1897, when it was first 

 observed. The only solution of the difficulty that 

 presents itself to our minds is that it inhabited 

 just the same kind of straw-heaps as are here 

 described, but that these had never previously 

 engaged the serious attention of botanical ob- 

 servers. Its distribution is partly effected by 

 artificial means— such as ploughing, and using the 

 straw to cover up root crops. 



The following list represents what has been 

 noticed by us as to the habitats of the Mycetozoa 

 in numerous localities ui the South of England. 

 The observations have ranged from the counties 

 of Merioneth to Norfolk, and from North Devon to 

 Kent : but the largest proportion of them are from 

 the counties of Beds, Herts, and Bucks. The few 

 notes that are not original are based upon speci- 

 mens that have been kindly forwarded to us by 

 Mr. A. Lister, Mr. C. Crouch, and Mr. Geo. Massee. 

 It is hoped that the list is sufficiently varied and 



Badhamia xitexs. ' 



extensive to warrant us in bringing the matter 

 under the notice of those wlio are interested in the 

 Mycetozoa. 



It will be seen that some genera have been 

 observed only on wood, but these could be further 

 gi-ouped as to the kind of wood on whicli they 

 live ; as, for example, Badhamia nitens, birch and 

 oak; Lycogala Jiarn-fuscum Ross., eini ; . Criiraria 

 aurantiaca Shrad., on Coniferae and Salix. 



Other species are apparently limited to straw- 



