495 
of Botany, Vol. 38, 1924 p. 27. Kylin (1923) p. 134. E. Chemin, Sur le développement des spores 
et sur le parasitisme d’Harveyella mirabilis Schmitz et Reinke. Comptes rendus d. s. de l'Acad. 
d. sc. Paris t. 184, p. 1187, 1927. 
Choreocolax mirabilis Reinsch, Contrib. 1875 p. 63, Taf. 53 et 54. 
Choreocolax albus Kuckuck, Choreocolax albus n. sp., ein echter Schmarotzer. Sitzungsber. d. K. preuss. 
Akad. d. Wiss. 1894. 
Although not described until 1875, this interesting parasitic alga was already 
observed by Lynesye. In Tent. Hydr. (1819, p. 47 tab. 11 B) he mentions and gives 
a drawing of some warts seated laterally on the branchlets of Gigartina subfusca y, 
tenuior (Rhodomela subfusca). The “puncta nigra” mentioned (I. ec. p. 48) which 
“potius pro massainterna 
hic illic magis conden- 
sata, quam pro semini- 
bus sumenda sunt’’, were 
probably the large inner 
cells rich in starch-grains. 
Specimens in Herb. Lyne- 
BYE of the named host- 
plant from Svinger, Nor- 
way, collected by Lyne- 
BYE in October 1817, bear 
several of these warts 
which are mentioned in Fig. 454. 
the label in similar terms Harveyella mirabilis. A, end of intramatrical filament(May) ; the last cell in begin- 
. Kr. ning division (to the right). B and C, longitudinal sections of Rhodomela with 
as in Tent. Hydr.; they intercellular filaments of Harveyella, pit-connections between the host and the 
proved on microscopical parasite. A, 560:1, B,C 350 : 1. 
examination to be sexual 
specimens of Harveyella mirabilis, one with procarps and a young gonimoblast, an- 
other perhaps a young male specimen. LIEBMAN also met with this species in 
December 1838 at Helsingor but referred it to Corynephora marina (Leathesia dif- 
formis). 
Our knowledge of the structure and development of this plant is principally 
due to the researches of Scumirz, Kuckuck and Srurcu cited above. The colour 
of the plant may be pure white in the living state, in particular in the large tetraspori- 
ferous specimens collected in May, but other specimens were feebly rosy or 
yellowish, apparently owing to the isolated cells of the host plant interspersed 
among the cells of the parasite. 
As pointed out by Kuckuck, the cells are devoid of chromatophores; it would 
be of interest to ascertain whether leucoplastids are also wanting. The cells represented 
in fig. 454 A after treatment with Nawasnın’s mixture’, showed filamentous bodies 
which are probably leucoplastids. The cells contain one nucleus as shown by Srurcn 
* See Karpechenko, The production of polyploid gametes. Hereditas IX, 1927, p. 349. 
