354 



NOTES ON MYCETOZOA. 



By Arthur Lister, F.L.S. 



Badhamia. ovispora Racib, — Mr. James Saunderg, of Luton, 

 discovered this species on old straw at Barton, Beds, on June 5tli, 

 1897. On further search among straw heaps at Stopsley Common, 

 which lies a few miles distant from Barton, when I had the pleasure 

 of being one of the party, more was found, and on July 28th a large 

 gathering was made at the same place by Mr. C. Crouch, of Kitchen 

 End, Ampthill. I am not aware of B. ovispora having been pre- 

 viously collected, except the original type obtained by Dr. Raciborski 

 on branches of Populns canesce72s DC. in Poland in 1884 (referred 

 to in Ih-it. Mus. Cat. jSbjc. 36). I have seen a glycerine preparation 

 of the type in the possession of Dr. Celakovsky, of Prague, and was 

 able to take a camera lucida drawing of the spores, and can there- 

 fore vouch for the specific identity of the present gatherings. The 

 sporangia are sessile, hemispherical, about 0*5 mm. diam., usually 

 crowded and confluent, or forming elongate and anastomosing plas- 

 modiocarps. The prevailing colour is white, but some clusters are 

 greyish pink, and others ochraceous. The thick sporangium-wall 

 is very fragile, and composed of remarkably large round granules of 

 lime 1-5-4 /x diam., which separate almost like sand on slight 

 pressure ; the calcareous outer crust rests on a delicately mem- 

 branous layer enclosing the spores. The capillitiura consists of 

 large irregularly-shaped lime-knots, often connected by broad tubes 

 filled with lime-granules, and uniting to form a cohmiella at the 

 base of the sporangium ; sometimes the columella is wanting, and 

 the capillitium is more regular in form with true Badhamia character, 

 but it is here and there reduced to slender hyaline threads. The 

 lime-granules filling the knots are of the same structure as those in 

 the sporangium-wall, and crumble down almost at a touch. The 

 spores are strikingly characteristic of the species ; they are free, 

 and vary in shape from ellipsoid to nearly globose ; they measure 

 from 10 to 16 /x by 8 to 10 /x diam., and are perfectly smooth as 

 seen under a magnifying power of 1600 diam. A ridge or fold runs 

 along one side in the direction of the long axis, and often gives the 

 appearance of an apiculus at the two ends. On drying, the spores 

 contract on the side marked by the aforesaid ridge, and take a boat- 

 shaped form ; when viewed under a moderate magnifying power, 

 they sparkle like glass beads, reflecting the light from their polished 

 surfaces ; the colour is olive-brown witli a purplish tinge. 



In several species of rhysanim, especially in P. comprcssiim, we 

 are accustomed to meet with a vitreous condition of the lime on the 

 sporangium-wall ; it appears to be in consequence of exposure to 

 rain, and is alluded to in B. M. Cat. 54. The solution of the lime- 

 granules and subsequent crystallization is a striking feature in 

 B. ovispora ; in some cases the sporangium is almost covered with 

 irregixlarly-shaped, crystalline nodules about 40-50 /x diam. 



The examination of old straw heaps in open fields has lately 

 yielded remarkably rich results, and I hope shortly to offer some 



