INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 935 



several centimetres. The impregnated oospore germinates without any 

 intermediate period of rest, and develops at once into a cellular fila- 

 ment ; this condition being described by Reiuke as that of the " resting 

 larva." In this state Ecinke believed he had detected the production 

 of " secondary spores," which, however, Falkenberg regards as a 

 pathological product. This condition is only of short duration ; in 

 six or eight weeks lateral branches are produced, diflfering altogether 

 in appearance from the primary germ-plant, consisting of plates of 

 tissue with marginal growth. At this stage the germ-plant perishes. 

 The impregnated female zoospores (zygospores) do not, on germina- 

 tion, produce at once a Cutleria-thallus, but a second generation, con- 

 sisting of flat creeping shoots, which develop as lateral branches from a 

 primary " germ-foot," and which differ materially from the ordinary 

 C«^/e>-/a-thallus, both in the direction of their growth, and in the 

 position of the growing jioint. 



The author considers the phenomena here described as a connecting 

 link between the conjugation of similar zoospores (zoogametes), and 

 the impregnation of a passive oosphere by mobile autheroids. 



Conjugation of Ectoearpus.* — It is now some time since Thuret 

 discovered, contrary to his first assertions in 1850, that Ectoearpus 

 possesses unilocular sporangia (oosporangia), as well as multilocular 

 sporangia (trichosporangia). The same authority is said to have 

 proved later on that the zoospores issuing from either of these forms 

 of sporangia germinate without any previous reciprocal contact. 

 Janczewski and Eostafinski have obtained the same result ; they say 

 that no conjugation takes place, neither at the moment of the emission 

 of the zoospores, nor during their germination.j Since that, however, 

 Eeinke has proved sexuality in the Ectocarpacete, and in Zanardinia 

 and Cutleria. Areschoug had already previously observed the con- 

 jugation of Dicfyosiphon, but by a method which gave room for some 

 criticism. In Acetahularia, Strasburger has observed that the zoo- 

 spores only conjugate when they issue from different spoi-angia. 

 Goebcl has proved analogous phenomena in Edocarpus pusilhis, which 

 is frequently found in the Bay of Naples on the great algae, particu- 

 larly on Codium tomentosum. He has seen the zoospores of this species 

 conjugate only when two neighbouring sporangia were open at the 

 same time. The same is the case with Ulothrix, according to Dodel. 

 There is, therefore, among the inferior cryptogams, a tendency to 

 cross fecundation. 



American (Edogoniacese. X — Professor Wittrock, the chief autho- 

 rity on the CEdogoniaceee, has monographed the American species, 

 including twenty-three of (Edorjonimn and eight of Bulbochcete, seven 

 species being altogether new. The family, as a whole, differs but 

 little from its European aspect, all the American forms belonging to 

 types which are also represented in Europe. Those of Greenland and 

 other northernmost parts of America are identical with those of 

 northern Europe ; while those from the southern districts differ 



* 'Bot. Zeit.,' xxxvii. (1878) pp. 117, 193. 



t ' Soc. des Sci. Nat. de Cherbourg,' 1873 ; Ibid., 1875, p. 9. 



X 'Botauiska Notiser,' Nov. 5, 1878 ; see ' Bot. Zeit.,' xxxvii. (1879) p. 312. 



