46 



of Tournefort, in which we are interested at present, is equal to Ficoides or 

 Ficus of Commelinus' Hortus Amistel (1097), equal to Ficoides or Ficus of 

 Plukinet Almag. Botanica 1 1606), equal to Echirw-melocactus of Ilermannus 

 Hortus Lugdbt. (1687). 



Commencing again with Linnaeus (1753), we find that he first described 

 the species Cactus mamillarius, which thus seems to stand as the type of 

 the genus. This genus of 2S species was not disturbed until 1812, when 

 Ilaworth. in his Synopsis Plantarum succulentarum, separated it into five 

 genera, Mamillaria, Echinocactus, Melocactus, Cereus, and Opuntia, discarding 

 Linngeus' name, Cactus. He called Cactus mamillarius Linn. Mamillari 

 simplex Hawworth, which was the only species of Linnaais that would 

 fall in the new genus Mamillaria. At this time ( 1812), Mamillaria con- 

 sisted of five species. In 1830 eight species were recognized. This state 

 of affairs was not molested until last year, when I)r. O. Kuntze published 

 his Revisio Genera Plantarum and re-established the Linnaan genus ( 'ac- 

 tus, which thus equals Mamillaria Ilaworth, changing over 300 species of 

 Mamillaria to the genus Carta*. In summary, we have Cactus L., re-estab- 

 lished by < ). 'vuntze (1891), MamiUaria Haworth (1812), Carta* L. (1753), 

 Melocactus Tourn. 1 171 it) in part. Ficoides or Ficus Commelinus (1697), Fi- 

 coides or Melocactus Plukinet (1796), Echino-melocactus Hermannus (1687). 



The revision of the genus Cactus, like the other genera of Cactacese, is 

 made under great difficulties, because of the lack of types, and insufficient 

 flowering material. Since this is true, and because a specimen is almost 

 useless without flowers, according to the present system of keys, we have 

 attempted with the types at command to revise the genus without using 

 flower characters but by using those parts of the plant which are always 

 present, the tubercles and spines. 



-OMK CAI SfiS ACTING PHYSIOLOGICALLY TOW \ Kl > 



cities. Py J. ('. Arthur. 



An auxaxometer fob the registration op the growtu OF STEMS IV THICK- 

 NESS. By Katherixe E. Goldex. 



The main feature of this auxanometer for measuring growth in thick- 

 ness is a balanced glass arm, supported near one end. The long end has 

 a bristle fastened to it that comes in contact with a blackened glass rod 

 carried round on a brass spool, the spool being revolved by a clock. 



