184 



SCIENCE-GOSSIP. 



[June ], 1S65. 



EiSH Moulds and Ely Moulds. — Several 

 times lias attention been directed in these pages 

 1o the mould which attacks fish in aquaria. Tliis 

 lias been either as a query or a brief reply. 

 The opportunity now occurs for making more ex- 

 tended observations on the subject. At page 10 

 appeared a communication on " A Dead Ely on the 

 Window," — this is singularly associated with the 

 present question. The little mould therein referred 

 to^ called Umpusina muscm, is the terrestrial state of 

 what seems to be an amphibious species, which in 

 its aquatic condition has been named Saprolegiiia 

 ferax, and generally regarded as an Alga, but some- 

 times as a Eungus. It is not our intention to enter 

 upon a dissertation as to its affinities and proper 

 place in the vegetable kingdom ; but our own opi- 

 nion, strengthened by the recent investigations of Dr. 

 De Bary and others on Eungi producing zoospores, 

 certainly is in favour of regarding this mould audits 

 allies as Eungi. If such a diseased fiy as those de- 

 scribed by W. M. B., in the paper already alluded 

 to, are cast into water and allowed to remain, it 

 soon developes a misty, filmy mouldiness around it, 

 in a similar manner to the mould on fish in aquaria, 

 and on the ova of fish, as well as upon molluscs and 

 some other bodies, and just such a mould as that de- 

 scribed and illustrated in the preceding page. 



There are four genera known, eacli containing 

 a greater or less number of species, and all bearing 

 a great family likeness to each other, growing in 

 Avater on similar substances, and doubtfully referred 

 both to Algffi and Eungi. The name of AcJiylapro- 

 lifera cannot but be familiar to all who have paid 

 any attention to disputed botanical questions. 



A brief description of the development of one of 

 these somewhat obscure vegetable productions must 

 serve as a tj'pe of the rest. The first appeai'ance 

 presented by it is that of delicate threads, which are 

 either simple or but slightly branched. These 

 whitish threads radiate in all directions from the 

 body whence they spring. The extremities of these 

 threads become filled with granular mattei*, as 

 figured on the other side (fig. 1), they gradually 

 swell, and a division is formed across the thread, be- 

 neath the granular contents, which become rounded 

 into little pellets (fig. 2). Each of these pellets 

 separates from the rest, becomes an ovate spore 

 which escapes by an opening at the top of the 

 threads (fig. 3). These spores in Saprolegnia have 

 two thread-like appendages, by means of which they 

 move about in the water for a period as zoospores, 

 imtil ultimately the motion ceases and germination 

 commences. In Acliyla prolifera the spores on is- 

 suing from the threads are at first enclosed in a 

 membrane, which soon ruptures and sets the zoo- 

 spores free. 



A second form of fruit is also produced on other 

 threads, lateral branches ending in globular sacs are 



formed, which contain resting spores (fig. 5), larger 

 than the zoospores. Similar branches contain 

 granular matter, which would appear to be anthe- 

 ridia, the function of which is to fertilize the resting 

 spores (figs. 6, 7, S). These large spores are called 

 Oogonia. Tlie walls of the globular sacs in which 

 they are developed are perforated, so that through 

 these perforations the resting spores are fertilized by 

 the antheridia. 



A third kind of fruit, described by Cienkowski, 

 appears to have been observed also by J. S. T., in 

 which a spherical sac, resembling those which con- 

 tain the resting spores, is produced on a side branch, 

 and contains spherical spores with a long tubular 

 neck (fig. 9), which bore through the walls of the 

 sac enclosing them and discharge minute swarming 

 bodies into the water; these have not hitherto been 

 known to germinate. Eurther information on this 

 subject may be found in the " Micrographical Dic- 

 tionary" under the head of Achyla, and also under 

 Sporendonema M. C. C. 



THE " STAND AUD" WASPS' NEST. 



"P|R. BINGLEY, at a recent meeting of the 

 -^-^ Sheffield Eield Naturalists' Society, gave a 

 very interesting account of a wasp's nest which was 

 exhibited. In April, 1864, he had tied some pieces 

 of the Standard newspaper to a string, for the pur- 

 pose of keeping the birds off some seeds he liad 

 sown in his garden at Whitley Hall. In May he 

 observed a number of small holes in the paper, as 

 if perforated by some insect. Watching it narrowlj', 

 he at length discovered a party of wasps at work 

 upon it. By carefully following them, he traced 

 them to an ivy bush, where he found them busily 

 engaged building the nest exhibited, which he be- 

 lieved he was correct in stating to be constructed 

 entirely out of the Standard newspaper. The 

 animals appeared in the first instance to puncture a 

 small hole in the paper, and then gather further 

 supplies by gnawing round its edges, working it 

 into pulp at the place, and after getting as much as 

 they could carry, flying off with it to the nest. The 

 comb was constructed simultaneously with the outer 

 shell. The formation of the entire nest occupied 

 until the middle of June, and the greater part of 

 four whole newspapers were consumed in this man- 

 ner before it was completed. To his surprise the 

 nest was evacuated by them in the first week of 

 August. 



The solubility of granite in pure water and in hy- 

 drochloric acid are among the tests of its value. An 

 indifferent granite was found to lose 0'25 per cent, 

 of its weight in the former and 5 per cent, in the 

 latter. — Aiisted^s Lectures on Practical Geology, 



