572 HUTCHINSON'S POPULAR BOTANY 



and Pitcher-plants ? The power of movement in the swarm-cells is 

 paralleled by similar movements in the antherozoids of many cryptogams : 

 and the development of cellulose is by no means a common feature among 

 animals. 



But however one may regard these Mycetozoa or Myxogastres, they 

 remain an exceedingly interesting group, such as may be studied easily 

 by all who walk in the woods and country lanes, and we shall try by 

 a few examples of different types to give some elementary idea of their 

 beauty and diversity of form and colour, such as may be acquired by 

 a pocket lens though for their serious and exact study the microscope is 

 required to be brought into use, as the determination is largely based upon 

 the character of the capillitium, the size and colour of the spores, and 

 so forth. 



One of the largest of known species is Brefeldia maxima, of which we 

 have already (fig. 186; given a photograph showing it in the plasmodium 

 stage. The appearance of this plasmodium to one who only knows the 

 "Myxies" as almost microscopic forms is astonishing. We have seen it 

 issuing from a large pine stump, flowing out over the bark and climbing 

 up the stems of plants at a short distance in sheets that would cover several 

 square feet. There were no visible cavities in the stump to all appearance 

 the wood was sound. But they issued as microscopic swarm-spores from 

 microscopic cavities, and multiplied by division on the exterior. A small 

 portion of such an outflow is shown in the photograph of the natural 

 size (see p. 149). After a time the creamy whiteness gets a pinkish tinge, 

 then brown, and a crust forms over detached oval portions two or three 

 inches long. The crust is somewhat shiny, of a dark brown colour, and 

 with an indistinct tesselated appearance. This is an sethalium or compound 

 sporangium, and the tesselated appearance is due to the fact that there 

 are a large number of sporangia packed closely side by side. The semi- 

 fluid creamy mass inside becomes a dry, fine powder like soot. The crust 

 contracts, splits and flakes off, leaving the spores (for such is the powder i 

 free to be blown out by the air-currents (fig. 719). 



Mucilago spongiosa. shown in fig. 717, also forms an sethalium, but it is 

 quite different in appearance from that of Brefeldia, the sporangia com- 

 posing it being more loosely compacted. Its creamy plasmodium may be 

 seen in autumn creeping up the stems of grasses and weeds in pastures. At 

 some distance up the stalks it consolidates into masses such as are shown 

 in the photograph, which are thickly covered on the exterior with crystals 

 of lime. Its spiny spores are dull purple in colour. Leocarpus fragilis may 

 frequently be found on pine stumps, with large, polished, brown sporangia, 

 clustered owing to the weakness and shortness of their stalks. Our photo 

 (fi.g. 721) represents it in the plasmodium stage creeping among moss and 

 pine-needles on a pine stump. 



The capillitium of some species expands to a remarkable size when the 



