ZOOLOGY AND BOTANY, MIOROSCOPY, ETC. 787 



and, in certain states, a true cell-wall of cellulose. The lowest family — the 

 Protococcaceae — exhibit further development in two directions, the perfec- 

 tion and differentiation of the individual cells, and the association of cells 

 into colonies or coenobes. The latter tendency leads to the Sorastrese, Pan- 

 dorineae, and finally to the Yolvociueae. The further differentiation of the 

 individual cell has advanced one stage in the Eremobiee or Characiaceae, 

 from which are derived the Multinucleatfe, comprising the Siphonocladaceas 

 and Siphoneee. The striving after a high development by the elaboration 

 of a single cell culminates in Vaucheria, or in such forms as Acetahularia. 

 Cell-division is already well displayed in the ConfervoidciB isogam^e, includ- 

 ing the Chroolepideae, Ulotrichacefe, Confervaceae, and Pithophorace^e. 

 From them evolution appears to have taken place in three different lines : — 

 (1) the ConjugatiB, including the Zyguemacese, Mesocarpese, and Desmidieae, 

 which evidently came to an abrupt conclusion ; (2) the Phfeosporeae, which 

 led, through the Cutleriaceae and Dictyotege, to the Fucaceae, the highest 

 type of " oogamous " reproduction, consisting in the impregnation of a com- 

 paratively large oosphere by a number of minute autherozuids ; the Syn- 

 geneticai being regarded as a retrogressive offshoot from the Phasosporeas ; 

 and (3) the Confervoidcfe heterogamfe, including the Sphferopleacete, CEdo- 

 goniaceae. and Coleochfetaceae, from which latter family the Pediastreae are 

 probably derived by retrogression. The Coleochfetaceae lead up dii-ectly to 

 the highest type of structure attained by Thalloj)hytes, the Florideae, from 

 the highest form of which we have probably several reti'ogressive branches, 

 viz. tbe Nemalieas, the Lemaneacete, and the Baugiaceae ; the author suggests 

 that the Ulvaceae may possibly be derived from the Bangiaceae by further 

 retrogression. 



Cause of the Turbidity of Water.* — Dr. C. 0. Harz describes a peculiar 

 appearance in the water of the Schliersee, in Bavaria, commencing when it 

 was covered by ice ; — a dense turbidity, at first of a green or blue tinge, but 

 becoming finally yellow-red or peach-coloured before finally disappearing. 

 This was due to enormous quantities of a Palmella, probably P. uvseformis, 

 which was attacked and finally completely destroyed by a peach-coloured 

 micrococcus, Clathroci/stis roseo-persicina. In addition were found also 

 smaller quantities of Beggiatoa alba, B. roseo-persicina, Clilorococcum 

 gigas, C. botryoides, Conferva homhycina, Cylindrospermum macrospermum, a 

 Baphidium, Scenedesmus acutus, and S. obtusus ; also several diatoms and 

 Oscillarias. 



Dissemination of Algae by Fish.f — Further observations on this subject 

 by Sig. A, Piccone confirm his previous conclusion as to the important part 

 played by herbivorous fish in disseminating seaweeds by feeding upon 

 them. The contents of the stomach and intestines of many species inhabit- 

 ing the Gulf of Genoa were examined, and found to contain large quantities 

 of different species of seaweeds, and very frequently the fertile jjortions. 

 Far the most important agent in this process is Box Salpa, in which were 

 found the remains of no fewer than fifty species of marine algje. In the 

 stomach and intestines of Sarcjus Bondeletii were found twenty-four species, 

 and smaller quantities in Sargus annularis, Pagellus Mormyrus, Labrax 

 Lupus, Scomber Scovibrus, Scorpaena Porcus, Labrus two species, and Belone 

 Acus ; while Box Boops, Cantharus lineatus, Pagellus Acarne, P. erythrinus, 

 Chrysophrys aurata, Dentex vulgaris, Xyphias gladius, Zeus faber, Scorpsena 



* SB. Bot. Ver. Miincben, Dec. 20, 1886. See Bot. Centralbl., xxx. (1887) pp. 286-7, 

 331-2. 



t Nuov. Giorn. Bot. Ital., xix, (1887) pp. 5-29. Cf. this Journal, 1885, p. 843. 



