580 Proceedings. 



where the species is common. The starchy nature of the rhizome has 

 long been known, and, according to Cheeseman, these thick rhizomes 

 were formerly collected and eaten by the Maoris, especially in the Ure- 

 wera country. I was curious to examine the starchy substance, and 

 accordingly squeezed the cut end of a rhizome in a minute drop of water 

 on the microscope-slide. I found the liquid was full of minute white 

 granules, which were only about O0025 mm. in diameter. These were so 

 abundant as to make the juice, when squeezed out, quite milky. Among 

 them were a few larger rounded and usually oblong masses. On adding 

 solution of iodine the larger masses stained a brown colour, showing the 

 presence of proteids, but they very quickly disintegrated into amorphous 

 brownish rlocculent masses. The small granules remained uncoloured. 

 On heating the semi-fluid material on the slide these small granules dis- 

 solved completely, but on addition of iodine -solution they were repre- 

 cipitated in a loosely flocculent form, and were stained a reddish-violet 

 or port-wine colour. These reactions appear to show that the granules 

 are probably erythro-dextrin, one of the cellulose-starch isomers (C 6 H 10 O 5 ). 

 On heating a small quantity of the clear solution with Fehling's solution 

 considerable reduction and deposition of cuprous oxide took place, shew- 

 ing the presence of dextrose. I estimated the amount of this dextrose 

 in a portion of a rhizome which was shred down and completely extracted 

 with hot water, and found it amounted to 1-38 per cent, of the whole. 

 Unfortunately, the whole amount of erythro-dextrin and dextrose together 

 was not estimated. I am inclined to think it will be found that the 

 material stored up in these rhizomes in autumn is erythro-dextrin, but 

 that as the spring growth starts this is converted into the soluble dextrose, 

 and thus is immediately utilisable in the formation of stem-tissue. These 

 rhizomes also contain a considerable amount of raphides. especially in the 

 cells near the surface, and the amount of calcium-oxalate found amounted 

 to 0"26 per cent, of the whole weight. 



It is desirable that the parasitic habit of these orchids should be more 

 closely investigated. I have no record of the roots on which they grow. 

 nor can I find that any careful examination of these has been made. The 

 casual collector has usually little time and few means to undertake such 

 an investigation, but any one dwelling in a bush district where these plants 

 are common could readily find out. This note is a preliminary one. as T 

 hope to be able to look into the matter again. 



P.S. — I placed a few portions of the rhizomes in damp moss in Sep- 

 tember last, covering them with leaves and humus, and keeping the whole 

 mass moist. Now (Kith December) they are throwing up stems with 

 scale leaves and rudimentary flower-buds. But the growth is thin ami 

 stunted, ami is evidently the product of the conversion of the material 

 stored up, not the assimilation of new food-material. No roots are being 

 developed, and presumably the specimens will die without coming to any 

 full development. 



Lecture. — Mr. G. M. Thomson gave ;i popular account, 

 illustrated by diagram and lantern-slides, of the " Life-history 

 of the American Lobster." 



Papers. — 1. "Fossils from Kakamii," by J. Allan Thom- 

 son, B.Sc. ; communicated by G. M. Thomson (p. 98). 



2. "The Scheelite of Otago," by A. M. Finlayson. M Sc. : 

 communicated by Dr. Marshall (p. 110). 



3. "Some Observations on the Schists of Central Otago," 

 by A. M. Fralayson, M.Sc. ; communicated by Dr. Marshall (p. 72). 



