NATURALISTS' FIELD CLUB

Evening Star, Issue 23370, 13 September 1939, Page 4

NATURALISTS' FIELD CLUB

FUNGUS-ANIMALS There was a good attendance of members of the Dunedin Naturalists’ Field Club at the indoor meeting on Monday, when Mr S. H. Rawson gave an address on the subject of the mycetozoa, or “ fungus-animals.” Some interesting specimens of these little-known “ fungus-animals ,” were handed round and a fine series of lantern slides was also used to good purpose in illustrating the subject. Mr Rawson explained how these tiny creatures, since thev fell neither within the scope of the strict botanist nor of the strict zoologist, had been rather neglected by the Now Zealand scientist, in spite of their undoubted attractions for those who can appreciate microscopic beauty. The ripe and dry sporangia, which form the stage which the collector hunts for, have indeed a great range of shape, structure, and colour, though, since chlorophyll is not found in this biological group, green is a colour which is not found amongst the mycetozoa. These sporangia, or sporevessels, are filled with spores which can be cast into the air in clouds under certain circumstances and distributed far and wide by air currents. The story of the life cycle of these spores is

an engrossing one. If one is fortunate enough to land in a suitable drop of moisture the spore swells and bursts, liberating a wriggling little blob of protoplasm equipped with a tail or flagellum —and this is the distinctly animal phase of the mycetozoon concerned, for it swims about feeding on bacteria. It appears that at its first cell division this cell divides into a male and a female cell and that these cells whenever they divide thereafter remain male and female respectively. There comes a time when these male and female cells fuse with one another, and then undergo rapid growth, even feeding on the unpaired species in the neighbourhood—a cannibalistic procedure.- The aggregation of paired cells forms a mass of jelly-like living substance which mav be tinted with various colours according to the species, and which may be called a plasmodium. This plasmodium may live in rotting wood or various trees—e.g., pine trees (but not, as far as is known, on totara or manuka), and may spend as long as five years in this form, drying up in dry spells and reviving again when moisture returns, but at length warmth and moisture and perhaps other factors induce it to complete the cycle and form sporangia again. In 1930 about 10 genera and 15 species were all that had been recorded for New Zealand, but Mr Rawson, working with the help of a few other enthusiasts, has brought the recorded •genera up to 24 and the recorded species up to 86, so that there is no lack of material in this field for the naturalist. There is more than a possibility, indeed, that one of the species which has been collected is distinct from any previously recorded, though its genus is quite well known. Those who seek the mycetojsoa should look for them from early spring to autumn and winter on decaying vegetation and dead wood, but they may also bo found sometimes oil living blades of grass or fern fronds and in other unexpected places. Displays of various plants were also presented by Miss H. K. Dalrymplo and Mr Douglas Coombes, and the evening closed with a vote of thanks to Mr Rawson and Mr Coombes.

OUTING TO STONY HILL. It was a lovely spring afternoon, and 12 members climbed the hill from the tanks on the Ravensbourno road to a patch of bush. The hillside showed signs of the hard winter and the heavy snowfall. Many trees are still to be found there, chiefly broadleaf, carpodetus, lancewood, and fuchsia. Nothopanax colensoi (the three-fingered panax) and N. arboreum (the five-fin-gered), as well as pseudopanas crassifolium (the lancewood) were noted. Many of the common _ ferns usually found around Dunedin still remain, but no filmy ferns were seen. The scrub consisted mainly of several var-

ieties of coprosma, on which grew th» mistletoe korthalsella, pittosporum, with its sticky fruits, myrtle, and corokia.