89 



the cane to fall. An examination showed that the part destroyed was 

 not more than one foot in length, from the ground upwards, and that 

 the tunnels bored were in possession of a parasitic fungus, Trichos- 

 phoeria sacchari, the surrounding tissue being blackened by the chain- 

 like macrospores of that organism, and the ants appeared to have 

 confined their depredations principally to this section. From the 

 blackened part, the fungus could be clearly traced by the discolouration, 

 which passing from black into deep red, then became gradually lighter 

 until it finally disappeared in healthy tissue, at some two feet from 

 the ground line. 



The attack on the plot has not been general, and seldom more 

 than one or two canes in a stool have suffered ; but it is considered 

 desirable to put the occurrence on record for future reference. 



Whether the attack is to be attributed to the nearness of wood- 

 land country — the natural breeding ground of the insect — or to a 

 possible scarcity of suitable food, or whether the attack has simply been 

 made on canes attacked by TricJiosphceria has yet to be determined ; 

 but it may be stated that there is evidence which points to the 

 latter conclusion, but further observations are yet needed to confirm 

 this view. 



There is also evidence that wood in buildings, or that in trees, 

 which has in any way lost its vitality, is first attacked by the 

 mycelium of a fungus which renders it a tempting food for the 

 " wood ant," a circumstance which would tend to explain the 

 destruction of timber which takes place in a damp atmosphere ; for 

 it is clearly certain that microscopic fungi are more quickly developed 

 in such places, than in a dry atmosphere. 



J. FT. Hart. 



May 14th, 1895. 



Circular Note No. 23. 



A Flight of "Parasol Ants." 

 On 25th May I had occasion to attend the Port-of-Spain Railway 

 Station, and proceeding thitherwards in the early morning I found 

 the road all along the route, from the Gardens to the Station, covered 

 by myriads of the winged form of the Parasol Ant known as Atta 

 Octospinosa, Beich. ; which is so common in the neighbourhood of the 

 Town of Port-of-Spain to the exclusion of its larger brother, Atta 

 cephalotes, or the woodland " Parasol Ant" the "Sauba" of Nicaragua. 

 Opportunity is taken of this occurrence to point out the lesson it 



