ALLANTOIN. 



r 



ALTERNATION. 



cipitated by sulphocyanide of potassium, 

 unless the solution is highly concentrated. 



Quinine. A solution of this alkaloid gives 

 with ammonia a perfectly amorphous preci- 

 pitate; with sulphocyanide of potassium it 

 gives small irregular groups of acicular 

 crystals, resembling those produced by 

 strychnia, but longer and more irregular 

 (PI. 7. fig. 8). When the precipitate is 

 produced in a test-tube, arid with a concen- 

 trated solution, it falls immediately as a white 

 powder composed of extremely minute 

 needles ; but when the solution is dilute, it is 

 deposited after the lapse of twenty-four hours, 

 in crystals from 1-4 to l-3rd of an inch in 

 length. 



BIBL. Anderson (T.), Edinburgh Monthly 

 Journal, viii. 



ALLANTOIN. A crystalline organic 

 substance found in the liquid of the allantois, 

 and in the renal secretion of the calf. As 

 artificially prepared, it is one of the products 

 of oxidation of uric acid. 



Its crystals form transparent colourless 

 needles and four-sided prisms, with mostly 

 dihedral unequal summits, PI. 6. fig. 1. They 

 are not very soluble in either cold or boiling 

 water ; more soluble in alcohol, but not at 

 all in aether. 



BIBL. See CHEMISTRY. 



ALLANTOIS. An oblong or pyriform 

 sac developed during a very early period of 

 embryonic life from near the end of the in- 

 testine. Its function is that of a temporary 

 embryonic respiratory organ. The capillaries 

 in the allantois of the chick are distributed 

 closely like those of the lungs of the Batra- 

 chia. 



BIBL. Wagner, Elements of Physiology, 

 translated by Willis. 



ALLICULARIA, Corda. 

 A genus of leafy Liverworts(see 

 JUNGERMANNIE.E), contain- 

 ing one British species, common 

 on hedge-banks. 



A . scalaris = Jungermannia 

 scalaris, Schrad., J. lanceo- 

 lata, Eng. Bot. (fig. 7). 



Jungermannia compressa, 

 Hook., which has stipules only 

 on the innovations, is included AiHcularia scala- 



Fig. 7. 



inthisgenusbyFriesandothers. ris - Imn ?ature 



T TT 1 TI -j.' 7 T sporange m the 



BlBL. Hooker, British Jun- opened perigone 



germannifs, pi. 61 ; Sowerby, (magnified). 

 EngL Botany, pi. 605. 



ALONA. A genus of Entomostraca, be- 

 longing to the order Cladocera and family 

 Lynceidae. 



Char. Shell quadrangular or roundish 

 obovate, striated or grooved longitudinally, 

 or reticulate ; inferior antenna short ; beak 

 blunt, directed forwards and upwards. Three 

 British species, freshwater. 



f Shell reticulated .............. reticulata*. 



' \ Shell striated or grooved ...... 2. 



("Anterior margin of shell nearly 

 2 J straight, shell brown ........ quadrangular is f . 



1 ^ Anterior margin of shell convex, 



L shell colourless .............. ovata. 



* PI. 14. fig. 4. 



t PL H. % 5. 



Alsophila excelsa. 

 Pinnule with sori. 



Fig. 9. 



BIBL. Raird, British Entomostraca, p. 121 

 et seq. pi. 16. 



ALSOPHILA, R. Fig. 8. 



Brown. A genus of 

 Cyatheaeous Ferns. 

 Exotic (fig. 8). Al- 

 most all the Alsophila 

 are tree-ferns. Sec- 

 tions of their petioles 

 exhibit fine scalari- 

 form ducts, the slits 

 between the fibres 

 forming many perpen- 

 dicular rows. 



ALTERNANTHERA, Forskal. A genus 

 of Amaranthacese (Flowering Plants), pos- 

 sessing remarkable branched hairs upon the 

 leaves. See HAIRS, of plants. 



ALTERNARIA, Nees. A 

 genus of Torulacei (Coniomyce- 

 tous Fungi). Microscopic fila- 

 mentous fungi, remarkable for 

 their flask-shaped, cellular 

 spores, produced in chains which 

 ultimately break up into the 

 single links (fig. 9). No British 

 representatives of this genus 

 appear to have been recorded 

 hitherto. 



A. tennis grows parasitically 

 upon other filamentous Fungi, 

 and it is common about Berlin, 

 Prague and other places. Corda 

 made the ripe spores germinate 

 on Cladosporium herbarum kept 

 moist. They usually first pro- . 



11 ^i i ._ Ai_ i Alternaria te- 



truded a filament from the neck, 



or attenuated projection, and 



afterwards others from the cells 



at the sides and opposite end of nified). 



the spore. These filaments became branched. 



BIBL. Corda, Icones Fung. in. p. 5. pi. 1. 

 fig. 16; Prachtfl. Europaisch. Schimmelbild. 

 p. 13. 



ALTERNATION OF GENERATIONS. 

 See GENERATION. 



nu i s . Fertile 

 spore -bear- 



