246 EITBACTS AND ABSTRACTS. 



each of a few longitudinal cells, which by division and swelling 

 become spherical, at the same time that a jelly-like substance is forming 

 round them. The segments composing these altered threads are then 

 disintegrated, and take on exactly the appearance presented by 

 Falmella. Vegetative reproduction is by means of 2-ciliated 

 zoospores, formed by conversion of the contents of the palmelloid 

 cells. "We would direct attention, in passing, to fig. 17, which shows 

 a zoospore with four cilia, two back and two front ; can this by any 

 possibility be a zygozoospore ? 



The Seedling of Rhipsalis Cassytha. (Ueber die Keimpflanzen 

 von Hhi'psalis Cassytha und dercn Weitcrbildung, von T. Ikmisch. 

 "Botanische Zeitung," March Slst 1876.) — The fact of the 

 occapional presence of short lateral shoots, presenting the 

 appearance of Cereus, on the stems of Rhipsalis salicornioides, must 

 long have been familiar to growers of Cactaceac, for this singular 

 structure is figured by Loddigcs (Cabinet, t. 369) so early as 1819. 

 "We believe, however, that the merit of pointing out its phylogenetic 

 signification is due to Ycichting (Jahrb. fur Wiss. Bot. ix.), who 

 observed it on old stems of JR. paradiixa. In the paper now under 

 notice will be found an exhaustive account of the successive ap- 

 pearances presented by seedling and young plants of li. Cassytha. 

 Some time after germination the opened cotyledons are seen to be 

 crowned by a fleshy mass studded with bundles of the spiny hairs so 

 abundant in Cereus. In the course of the second summer the main stem 

 becomes much elongated andtetraquetrous, the angles beingoccasionally 

 furnished with bundles of spines, and immediately above the cotyledons 

 short secondary shoots are given off". By the following summer 

 the main stem has become more lengthened, while the secondary shoots, 

 which present less the appearance of Cereus than does the main one, 

 have developed shoots of a third order, which look still less like 

 Ctrius. In this way we arrive finally at the thong-like branches 

 familiar to everybody. 



All these tacts point without ambiguity to the line of descent along 

 which Rhipsalis has been derived ; at the same time they render null 

 a lather enticing a priori view that this genus may be the Cactaceous 

 ancestor ; it must now, of course, be regarded as a breaking away from 

 the normal habit exhibited by its fellows towards the ordinary method 

 of growth, the axis ramifying and losing its crass nature to a conside- 

 rable extent. "We should be glad to see taken in hand an inquiry 

 into the early history of all the other genera of this curious family, so 

 that the phylogeny of the group may be constructed on a firm basis. 

 In the " Gardeners' Chronicle" for May last will be found an excel- 

 lent wood-cut showing R. salicornioides, with its Cereus-\\ke. branch. 



The Ivfixience of Light on the Colour of Flowers. (TJeber 

 den Einfluss des Lichtes auf die farbe der Blvithen, von E. 

 Abkenast. " Botanische Zeitung," January, 1876.) — This paper 

 is a record of experiments undertaken to ascertain what effect 

 is produced on the colour of flowers when the plants bearing 

 them are completely deprived of sunlight. The subject is introduced 

 by B fhort account of prior results obtained on the Fame field ; thus 



