ZOOLOGY AND BOTANY, MICROSCOPY. ETC. 079 



up bis observations witb tbe conclusion tbat tbe production <i lepto- 

 forms of Puccinia and utber genera of Uredineae bas no coniiection witb 

 eitber tbe systematic position or tbe anatomical cbaractcristics of tbe 

 bost-plant ; it appears ratber to depend on climatal conditions. 



Tubsracese and Elaphomycstes,* — Dr. E. Hesse makes tbe re- 

 markable statement tbat tbe Tuberaceae and Elapbomycetcs sbould bo 

 plac! d, if among fungi at all, on tbe extreme limits of tbe Mycetozoa. 

 In all if tbem tbe structure wbicb is known as tbe receptacle or fructifi- 

 cation owes its origin to swarm-cells, wbicb possess tbe capacity, under 

 certain conditions, of associating tbemselves into compound bodies, 

 varying greatly in form, size, and colour, but wbicb normally go tbrough 

 certain regular stages of development, and finally, after a variety of 

 cbanges in form, combine into tbe cbaracteristic fructifications of tbe 

 Tuberaceae and of ElapJiomyces. Tbat wbicb bas bitberto been regarded 

 as tbe clnse of tbe develojiment of tb< se fungi, tbeir process of deliques- 

 cence or decay, is in reality tbe commencement of tbe true period of 

 reproduction. Tbe small masses of swarm-cells into wbicb tbese bodies 

 break up resemble quartz-grains in appearance, but are as soft as wax. 

 Tbey are formed especially from tbe dissolution of tbe glebe and of 

 warts and scales, and are found in enormous quantities in tbe bumus of 

 tbe soil, wbei'ever tbese fungi are decaying. 



Tbe autbor's observations were made on Tuhrr raaculatiim and exca- 

 vatum, Balsamia frarjiformis, and a number of otber Tuberacete and 

 Elapbomycetcs ; aiid be believes tbese observations to bold good witb 

 regard to tbe Hymenogastreae generally and the typical Lycoperdaceas, 

 such as Lycoperdon, Bovista, Geaster, Polysaccum, and Sclerodenna ; 

 and also tbat tbe warts on tbe receptacle of tbe Hymenomycetes may 

 bave a mucb more important signification than bas baen generally 

 ascribed to tbem. 



Tb3 autbor disputes tbe parasitic nature wbicb bas been assigned to 

 the true Tuberaceae, believing tbem all to be true sapropbytes, wbile 

 Elaphoinyces may part ike cf botb cbaracters. 



Synthesis of Lichens.f — M. G. Bonnier records the results of a 

 series of experiments on the synthesis of lichens, in which care was 

 taken to avoid previous errors by using only perfectly pure spores of 

 Algae previously determined, and by preventing the access of other 

 spores. The mode of culture was in Pasteiu'-flasks or in cells specially 

 prepared, and tbe substratum employed was pieces of rock or bark free 

 from other organisms and sterilized at a temperature of 115^ C. Still 

 tbe results were sometimes negative, or foreign organisms resulted from 

 tbe access of air at tbe moment of sowing. In others lichens were 

 obtained by synthesis corresponding in every respect to those tbe spores 

 of which were sow^n. 



1 be Algae employed were Pleurococcus vulgaris, Protococcus botryoides, 

 P. viridis, TrenfepoMia umhrina (?), T. ahietina, T. aurea, Stichococcus 

 hacillaris, and Vaucheria sessilis ; and the lichens obtained by sowing in 

 conjunction with them the spores of the corresponding species were as 

 follows : — With Proto'occus — Physcia parietina, P. stellaris, and Parmeha 

 Acetabulum ; with Pleurococcus — Lecanora ferruginea, L. subfusca, 



* Eot. Centralb!., xxxviii. (1889) pp. 518-20, 553-7. 



t Ann. Sci. Xat. (Bot.), ix. (1889) pp. l-3i (5 pis. and 6 figs.) 



