lp:athkr from cacti 99 



The wood of the sahuaro yields a light and strong building- 

 material much used by the Papagoes in making the picketed 

 walls of their jacails or in making barriers around small 

 gardens or corrals. Illustrations of such cases are to be seen 

 in the city of Tucson. Recently Mr. Fred. C, Wright has 

 discovered a process of dehydration and tanning that will 

 greatly increase the usefulness of the sahuaro. This process 

 is described by him in a separate article in this number. 



A very remarkable instance of pseudo-parasitism was 

 found in a large specimen of the sahuaro in the Quijotoa 

 valley during the course of the expedition. An Opiintia 

 with three main branches was seen growing from cavities at 

 the apex of a large tree which w^as otherwise normal in 

 appearance. Seeds of the Opiiutia had probably been carried 

 to the summit of the sahuaro and germinating in one of 

 the cavities, had found a suitable substratum in the decayed 

 material which had formed there. 



Similar attachments to other plants have been observed; 

 a prickly pear near the Desert Laboratory is rooted in a knot 

 hole of a palo-verde {Parkinsonia micro phylui) and a large 

 Opunlia was seen growing from the sinus of a stem of Yucca 

 validii near Tehuacan in southern Mexico. Prof. W. L. 

 Tower reports that such arrangements are by no means un- 

 common still further to the southward. 



(coNCLunp:D in june number.) 



LEATHKR FROM CACTI: SOMETHING NEW. 

 By Frederick C. Wright. 



One day, over a year ago, the writer, while handling 

 a piece of bisnaga {Echinocactus zvislizeni) noticed, after 

 the water it contained was pressed from the fiber, its 

 remarkable strength and pliability, and resemblance to 

 leather. Upon drying it became brittle and chalklike. 



In an effort to obtain strength and pliability in the 

 fiber after drying, I began a series of experiments in a crude 



