XI. 

 NOTES ON THE ]\[YCETOZOA, WITH A LIST OF SPECIES FROM 

 HERTFORDSHIRE AND BEDFORDSHIRE. 



By James Saundeks. 



(Communicated by A. E. Gibbs, F.L.S.) 



Read at St. Albans, 15th November, 1892.* 



If there be any trutli in tlie assumption that all creatures which 

 inhabit the earth have descended from some few primordial forms of 

 life, it will readily be gnmted that the two great kingdoms of 

 animated nature may touch at numerous points; that here and 

 there they coalesce or diverge, and that there may be existences 

 which combine some of the features of both. To these we may 

 surely relegate the Mycetozoa. They have at least three well- 

 defined stages of existence : the distributive, in the form of minute 

 spores, myriads of which are borne as impalpable dust by the 

 country breezes ; the creeping stage, when, for an indefinite period, 

 it may be weeks or months, numbers of these spores, having thrown 

 off tlieir cell- coverings, coalesce, and creep about on decayed leaves 

 or in dead wood; and the mature stage, in which, having ceased 

 their wanderings, they become sessile, and produce capsules. From 

 this it will be seen that they exhibit the curious phenomenon of 

 alternation of generations ; that is, if we may assume that the 

 Plasmodium stage is characterised by wholesale conjugation, and 

 hence is "the analogue of the zygospore" (Sachs, 'Text-book of 

 Botany,' p. 263). Possibly this may not be regarded by some as an 

 instance of true alternation of generations, but it at least presents 

 close analogies with this phenomenon. 



It is the creeping stage which has the greatest fascination for 

 an observer, as it is both curious and singular. It was only after 

 many months of patient investigation that we were rewarded by 

 the discovery of a Mycetozoon in this stage. The ive covers two 

 personalities, a juvenile enthusiast still in his teens, and the writer, 

 the latter often finding material assistance from the shai-p vision of 

 his more youtliful coadjutor. On the occasion referred to, we had 

 just reached the edge of an opening in a damp Hertfordshire wood; 

 lying near to us was a large trunk of an oak, which, having been 

 felled many years ago, was not only saturated with moisture, but 

 was thoroughly decayed. Overshadowing it were tall fronds of 

 bracken, and straggling sprays of bramble. Running our eyes 

 along its rugged bark, adorned here and there with mosses and 

 fungi, we were gratified to see yellow veins of a substance unlike 

 anything we had before seen. It covered a space over a foot in 

 length and several inches in breadth. It was somewhat viscid, 



* The Author exliibited coloured drawings of the Mycetozoa executed by the 

 Misses Lister, and photographic slides shown by the oxy-hych-ogen lantern ; and 

 a slide with living plasmodium which had thrown out pseudopodia during the pre- 

 ceding tweutv-t'our hours was also shown on the screen by the lantern-microscope. 

 This is probably the first time that plasmodium has thus been shown to a scientific 

 society. — Ed. 



VOL. VII. — PART V. 11 



