OF ARTS AND SCIENCES. 259 



the ScrophulariacecB, and to some observations made by his 

 pupil, Mr. Clark, several years ago, upon Mimulus^ showing 

 that this genus of the AntirrJiinidece not rarely has the lobes 

 of the lower lip of the coralla external in aestivation, as in the 

 RhinanthidecB. Professor Gray had recently noticed the same 

 thing in an anomalous still unpublished Pentstemon, which 

 presented both modes of aestivation in different flower-buds of 

 the same inflorescence. 



The Corresponding Secretary communicated, from the au- 

 thor, the following 



" Synopsis of the Cactacecc of the Territory of the United 

 States and Adjace?it Regions, by George Engelmann, 

 M. D,, of St. Louis, Missouri, 



" The only Cactus known to Linnaeus from the countries north of 

 Mexico was his Cactus Opuntia (Opuntia vulgaris). Long after 

 him, more than forty years ago, Nuttall, the pioneer of West Ameri- 

 can botany, discovered two Mamillaricz and two Opuntice on the 

 Upper Missouri, and again, twenty years later, in California, a new 

 Echinocactus, About ten years ago we became acquainted with nu- 

 merous new Cactacese, in Texas through Mr. F. Lindheimer ; in New 

 Mexico through Dr. A. Wislizenus ; and in Northern Mexico through 

 the same explorer and Dr. J. Gregg : some others (and among them 

 the giant of Cacti) were indicated in the Gila country by the then 

 Lieutenant W. H. Emory. Soon afterwards Mi'. A. Fendler col- 

 lected several new species about Santa Fe. Mr. Charles Wright, 

 a few years later (1849), discovered in Western Texas and Southern 

 New Mexico still other undescribed Cacti. 



" But the greatest addition to our knowledge of the Cactacese of the 

 southern part of the United States was made by the gentlemen con- 

 nected with the United States and Mexican Boundary Commission, at 

 first under Colonel Graham, and subsequently under Major Emory. 

 Science is indebted principally to Dr. C. C. Parry, Mr. Charles Wright, 

 Dr. J. M. Bigelow, Mr. George Thurber, and Mr. A. Schott, for val- 

 uable collections of living as well as dried specimens, and for full 

 notes taken on the spot. 



" About the same time, Mr. A. Trecul of France, and after him Dr. 

 H. Poselger of Prussia, traversed Southern Texas and Northern Mexi- 

 co, collecting many Cactaceoe, and increasing our knowledge of this 

 interesting branch of botanical science. 



