228 



ccnild have licen iio loss of oxalate of lime on desiccation, and, as 

 a matter of fact, we found as many crystals on microscopic ex- 

 amination of dried Arums as we had found in the fresh tubers. 

 We explain this apparent anomaly in the following simple man- 

 ner. In the fresh condition of the tubers, the bundles of crystals 

 of oxalate of lime are cone-shaped, more or less, the sharp points 

 covering a wide area, and forming- the base, but in the drying of 



STRTKTITKI'; OF TIIK KALO ("ORM. 

 TraiiHvt'rso section tliroiiifli a curiii of Pi'idli'i ulmiln. The staivli-coii- 

 taiiiinjf Itarcncliyiiia is (iiiitc moist, and very firm. 'Die iiaik is botii scaly 

 ami (ilirous. 'i'lic lal ici fcroiis tissue is conspicuous. 



the tubers, the needles appear to arrange themselves more or less 

 ])arallel to one another, and the sharp points thus cover i smaller 

 area. And thus, instead of each crystal acting as a separate 

 source of irritation and penetrating the tissues, the bundles act 

 as a whole." 



The acrid effect of the crystals, or raphidcs. is destroyed by 

 drying, boiling, or steaming the corm. 



