DR. HORATIO WOOD OX FRESH WATER ALG.E 197 



minutes. Even with this cement, and the utmost care in mounting, 

 the cabinet should be occasionally inspected, for there will always 

 be some slides into which air will penetrate. When such are found 

 efforts may be made to stop tbe leak by new rings of cement over- 

 laid upon the old ; but very often entire remounting of the speci- 

 men is the only satisfactory cure. 



SPILOC^EA POMI. Fries. 



This cosmopolitan fungus has made its appearance this 

 autumn in what would seem to be stronger force than hereto- 

 fore, threatening some crops with destruction. It appears at first 

 beneath the cuticle of the fruit, then breaks through in circular, 

 often confluent, patches, of a dark brown colour, bordered by the 

 lacerated margin of the cuticle. The microscope reveals a mass of 

 short septate threads, which are simple, and closely packed together, 

 each one terminating in an ovate, caducous joint, wLich has all the 

 characters of a spore, and ultimately becomes at least uniseptate. 

 The threads and spores are slightly coloured of a smoky-grey tint. 

 From these particulars it will be seen how near Spiloccea i^omi 

 approaches to such species of Cladosporium as C. dendriticum, of 

 which it is probably only a condition. In the "■ Gardener's Chro- 

 nicle" for Sept. 20th, it is supposed to be a state of Helmiii- 

 thosporium pyrorum. At any rate, mycologists seem to be agreed 

 that it is not an autonom^ous plant, and is closely related either to 

 Cladosporium or Helmintliosporium, From our own examination, 

 we are at present more disposed to refer it to the former than to 

 the latter. Further investigation, at a later period, might, perhaps, 

 modify this opinion, but at present its characters seem to approxi- 

 mate so closely to Cladosporium dendriticmn, especially the variety 

 orbiculatum, that we consider the probabilities strongly in favour of 

 that species. — M. C. Cooke. 



