44 one on the tor of eoch stonelet. The nuraher of these flovrering 

 pebbles increeised everj day until there v^^ere hundreds of them on 

 the otherwise hare veld; It v;as ^■^esem'bry&nthenium truncetellum, 

 Hpr-. J which occurred rather plentifully in this locality. " liie 

 rese.ra'^lfnce to pebbles must be very greet for anyone to frequently 

 v/plk over the p;round on which they grow without discovering thet 

 they v/ere not stones until flov;ers appeared. But. Dr. ^'^-arloth is 

 quite wronp; in his identificetion of the nlant, v/hich I have no 

 doubt whatever is a snecies of Lithops unknown to me et present. 

 "?or ^'. truncatelTum grows in tufts, does not resemble pebbles, but 

 is p-laucous -green an:5 do+ted, and hs ? li^ht stravr-yellov' flov/ers 

 th<^t only oren in the evenin'^. I have piven an account of the' 

 resemblance o^ the'se '"lantr; ':ones of p. 350 of "Volume L-2i. , 

 and have also there statpci - r;. exnlrined that thev all belong to 

 the the small rroup knovm as %'indowed rl^nts." ^le window, 

 however, is sometimes quite obscured by coloured pigment, which 

 acts as a screen to soften the li.^rht, yet does not prevent it 

 from T^enetratin/^ into the interior of the r^lant and reaching 

 the c^loronhvll layer (see i"ig. 112. p. 251, Vol. I^^. 



".■hen these plants are very young and have only a central 

 orifice, there is nothing in their external appearance to distin- 

 guish any of them from the genus Conophvtum; compare, for example, 

 ^i^. 84, H, with 84, 0, on p. 297, and with ?ig. 97 on p. 223," 

 Voll L:ct. But '"hen the adult condition vath a fissure allv across 

 the tOT" is assumed, or the plant flov/ers, the distinction between 

 the two genera is very obvious. '>'hile, in anj of its stages, if 

 a longitudinal section through a plant is made, the peculiar dis- 

 position of the chlorophyll layer, as shown in ^ig. 112, p. 251, 

 Vol. I-"^"^. , V'ill at once serve to distinguish this genus from 

 Cononhytum, in v/hich the chlorophyll layer covers the v.7hole surface. 



Although in nature these pl'^nts grow buried in the soil with 

 the tO'- level with or just risj ng above the surface, they often 

 refuse to rrow in th?t '''ay in this country, ^or if plented with 

 their to-ns just above or level with the soil, I have found thpt 

 the -fjrst new growth thrt is made in most cases rises far above 

 the ground level, doubtless due to the absence of such intense 

 li^ht PS they e-et in their oy.ti country/. On the contrary, I have 

 on^ r.Tpp+ Q-f L. Lesliei that I planted over two years ago with its 

 to^ level with the earth in. the TOt, thet has in no way changed 

 or made anv attemr^t to develoi" a new growth since it was pl^^^nted, 

 but has remained plum^^ and he^^lthy all that time, and has not flov/- 

 ered. But planting them level rath the earth in this country is 

 to rjsk their loss bv rot, as I have found from experiment, for 

 it is very difficult to knovj when the moisture in the soil is 

 greptar tbon the ^^lant will endure at any particular season, -^'or, 

 as I have previously istated, the v/rtering of these plants is f n 

 r^rt requirin?r s^ecia"* knowledge. If sufficiently watered at the 

 ^ro^er season the"!'' do not flower, and if overwatered they rot. 

 The thermom.eter and dr7fness of the atmosr^here should also be 

 consulted as fruides to the amount of vrater th.-^jt should be riven 

 E'nd how often it should be a^f^plied^ for a tablespoonful may be 

 enough for three vreeks in June or -December, yet not more than 

 enoiT-'-" -^or t-"'o or three days in August. I have found L.fulviceps 

 and L. optica to be esi^eciplly sensitive to a little too much v/ater 

 at the v/rong season. 



The ■nlant I described in the 'J^ournal of the i'innean -^^ociety, 

 Vol, 45, r-, 69, as I'esembryanthemum locale, and associated with 

 ST>ecies of this genus, may belong here, but it only known from 

 i^n im^e-^fect, dried si-ec1men, and cannot be prorerly placed until 



