Coker: Achlya DeBaryana Humphrey 



321 



into sections containing dense protoplasm, each section being a 

 chlamydospore. As with other chlamydospores, these will later 

 either become sporangia or give off slender hyphae, sometimes 

 many of them. Sometimes in their formation chlamydospores 

 begin to break apart by bending backward as shown by the apical 

 one in fig. i. They rarely become entirely detached. The 

 sporangia vary a great deal both in size and shape. At one ex- 

 treme are those that are large and stout and rounded at the end, 

 as in figs. 3 and 4, and at the other are long, slender forms that 

 are drawn out to a narrow point, which is often bent, as in figs. 

 5 and 6. 



In typical cases the spores on escaping act as usual in species 

 of Achlya, forming a rather perfect sphere at the tip of the 

 sporangium. Through long observation, however, cases have not 

 rarely been seen where the spores fell apart to a greater or less 

 degree, with the resultant formation of a community of detached 

 groups, as shown in fig. 6. It is this variation from the usual 

 course that led, fortunately, to the settlement of the uncertainty 

 that has existed until now as to the presence or absence of a 

 gelatinous matrix in the sporangium that is instrumental in caus- 

 ing the expulsion of the spores. I had long ago convinced myself 

 of the existence of such a substance from the behavior of the 

 spores in emerging in species of Achlya under usual and unusual 

 conditions. The formation of a little emergence-papilla just 

 before the escape, the rapidity and violence of the escape when 

 followed by immediate quiescence (the sudden popping of a spore 

 under constriction through a smaller opening would seem im- 

 possible under its own steam) and the frequent retention of some 

 of the last spores in the sporangium are all strong evidence of 

 mechanical propulsion under inside tension. And the presence of 

 cilia on the escaping spores (a point that is still in dispute^) could 

 scarcely modify the force of the evidence. The actual proof, 

 however, of the presence of such a jelly was still lacking until 

 presented under the conditions shown in fig. 6. If such a brother- 

 hood of newly-emerged spores be disturbed, the zi^hole archipelago 

 zvill move as a unit, showing beyond a doubt that they are all 

 bound together by a jelly that surrounds them. And it is the 



° See Horn, L. C, p. 221. 



