ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 85 



of them disappearing except one only, which forms the subhymenial 

 layer. The hypothecium is entirely vegetative in origin and arises 

 from the cortical cells. He contrasts this development with that of 

 Parmelia acetabulum, in which the hypothecium is a product of the 

 ascogonium, and the ascogenous hyphas rise from the hypothecium 

 through the subhymenium giving it a generative character as contrasted 

 with its vegetative character in Usnea. The author concludes that 

 Parmelia and Usnea are not so closely related as has been supposed, 

 though he states that other Parmelia, may not conform to this type. 



A further study was made of Cladonia types with a view to throw 

 light on the nature of the fruit in this family — whether the podetium 

 is a secondary thallus or a highly developed excipulum. He quotes the 

 work and views of various workers, and gives his own results. In Bceo- 

 myces he finds the stalk to be an elongate excipulum, in Sphyridium a 

 small typical podetium or secondary thallus, and in Icomadophila a stage 

 between the two forms. Further, he finds that Bceomyces is apogamous, 

 since neither carpogonia nor trichogynes could be discovered. In Icoma- 

 phila he found both organs as well as numerous spermogonia, in 

 Sphyridium carpogonia were much reduced and spermogonia were rare. 

 Nienburg considers that there are not sufficient data to determine the 

 nature of the Cladonia podetia. 



Mycetozoa. 



New Myxomycete.* — Louis Leger describes an organism allied to 

 the Mycetozoa, or rather perhaps to the Acrasieae. He found it living 

 as a parasite in the bodies of Coleoptera from Algeria. The vegetative 

 condition is to be found in or between the adipose cells of the insects, 

 more particularly in the genital organs. The youngest stages are ovoid 

 or spherical in form, with one nucleus ; later the form is amoeboid and 

 multinucleate, with from 2 to 8 nuclei. Nuclear division is by mitosis. 

 The vegetative bodies increase by division. At the termination of this 

 stage the substance breaks up into small uninucleate spores, though some- 

 times there are large multinucleate spores also. The Coleoptera do not 

 seem to be seriously incommoded by the presence of the parasite. Leger 

 names it Sporomyxa scauri g. et sp. u. 



Cultural Experiments with Acrasiese.t; — Ernest Pinoy undertook 

 a research to decide the connection, if any, between bacteria and 

 mycetozoa. Dictyostelium mucoroides had been described as parasitic 

 on bacterial colonies, and Pinoy proved this to be true. He isolated 

 a fluorescent bacterium, and found that the spores of D. mucoroides 

 would not germinate without the presence of this bacterium. He fonnd 

 also that the ruyxaincebre produced from the spores were nourished 

 by the digestion of bacteria in their vacuoles, and that a diastase is 

 formed which he calls acrasidiastase, by aid of which the bacteria are 

 digested. The author examined by similar methods two other members 

 of the group, Dictyostelium purpureum and Polysphondylium violacetnu. 



* Cornptes Rendus, cxlv. (l'JOT) pp. 837-8. 



t Ann. Inst. Pasteur, xxi. (PJU7) pp. 622-50 (i pis.). 



