242 



HA RD WICKE' S SCIENCE- G OSSIP. 



in the withering of the petals and the swelling of the 

 ovaries. 



One flower of Disa grandiflora was similarly treated, 

 and in a few days the flower had faded, and the 

 ovary was observed to be swollen. 



A terminal flower of Ionopsis utricularioides was 

 also similarly treated, and the result was the same. 



So sensitive to external stimuli are some orchid 

 flowers, that I found the sleeve of a lady's dress, which 

 accidentally rubbed against a terminal flower of 

 Stanhopea ligrina, had caused it to wither in two days 

 after its expansion. 



On another occasion I observed that a small fly, by 

 walking over the stigmatic surface of a cut flower of 

 Odontoglossum rossii majus, on a table in my room, 

 resulted in the withering of attractive parts, and a 

 marked swelling of the ovary. The fly did not 

 remove the pollinia, for it was caught and carefully 

 examined with a lens, but no trace of pollen-grains 

 could be detected on it. The flower was also exa- 

 mined, and the pollinia were found entire and 

 undisturbed. 



On another occasion the stigmatic surface of 

 Miltonia russelliana was irritated by a human hair 

 for several seconds, and was then withdrawn : this 

 operation resulted in the withering of the attractive 

 parts of the flower and the swelling of the ovary. 



In some instances I found the degree of sensibility 

 to be diminished or intensified in flowers of the same 

 plant, as well as in flowers of the same species of 

 different plants. 



In spite of the extreme sensibility of orchid flowers 

 to external stimuli, and their many and varied adapta- 

 tions to secure cross- fertilization, they set an 

 exceedingly small amount of good seed, which is 

 probably due to the degeneracy of the essential organs, 

 "the structure of which," says Professor Henslow, 

 "when microscopically examined, at once becomes 

 apparent. First, with regard to the pollen. Instead 

 of its being in well-formed distinct grains, each with 

 its extine and intine, their development is arrested 

 and, while still in contact, a common extine clothes 

 the whole of each massula. Moreover, it is only after 

 the pollen-mass has been placed upon the stigma, that 

 the development is continued. With regard to the 

 pistil, the first sign of degeneracy is seen in the 

 parietal placentation which prevails, and more 

 especially in the rudimentary character of the ovules, 

 every part of which is degraded. Even after fertiliza- 

 tion the embryo cannot grow to maturity, but remains 

 in the pro-embryonic condition. Having no albumen 

 or nucellus-tissue wherewith to nourish the embryo, 

 the suspensor does its best by elongating and escap- 

 ing from the micropyle, and then, fastening itself 

 like a parasite upon the placentas, extracts nourish- 

 ment therefrom, the result being that myriads of seeds 

 never succeed (at least in cultivation) in developing 

 even the pro-embryo ; and one can only infer that 

 such is the case in nature." 



A NEW BRITISH WORM. 



By the Rev. Hilderic Friend, F.L.S., 

 Author of "Flowers and Flower-Lore," etc. 



I RECENTLY received a consignment of earth- 

 worms from the neighbourhood of Bangor, 

 which contained, in addition to more than one species 

 new to Wales, one which is new to Britain, and 

 probably also to science. I have named it Allurus 

 tetragonurus, the reason for which may at once be 

 assigned. 



In 1874, Dr. Gustaf Eisen published in the Ofver- 

 sigt af Kongl. Vetenskapp-Akad., No. 2, a paper on 

 New England and Canadian worms, in which he 

 described among others a tiny species from Niagara, 

 which he regarded as the type of a new genus. This 

 genus he named Tetragonurus, or the quadrangular- 

 tailed, and supplied the following diagnosis : — 



" Body cylindrical in front, quadrangular behind. 

 Male pores on segment II [= the 12th segment 

 according to our English mode of reckoning], setae in 

 approximate pairs, lip or prostomium not dividing 

 the first ring or peristomium. It comes nearest to 

 the genus Allurus, from which it is distinguished, 

 however, by the position of the male pore, which 

 in Allurus is on segment 12 [= 13 in English], but 

 in Tetragonurus on 11 [= 12], as well as by the 

 lip failing to cut the buccal segment or peristomium." 



Eisen next supplies details of the species Tetra- 

 gonurus pupa. " Lip or prostomium small, acumi- 

 nate in front, pallid, not dividing the peristomium. 

 Male pores small but conspicuous ; the girdle pro- 

 minent, usually composed of five segments, namely, 

 17-21 [= 18-22]. Tubercula pubertatis conspicuous, 

 three on each side of the girdle, occupying the iSth, 

 19th, and 20th segments [= 19, 20, 21]. About 

 40 segments in all, length about 25 mm. 



Some Swedish comments are added, from which, 

 in addition to the foregoing facts, we learn that there 

 are only six segments between the male pore and the 

 first girdle segment. The tubercula are in the form 

 of a wart-like prominence or keel, extending over 

 three segments. The girdle is well marked and 

 easily distinguished from the adjoining portions, and 

 stretches over five segments, one of which is before, 

 and the other behind the segments bearing the 

 tubercula. The colour is sienna brown, becoming 

 light red on the back part. The worm closely 

 resembles Allurus, to which it approximates more 

 nearly than to any other, if one has regard to the 

 living forms ; while it also frequents similar habitats, 

 namely such places as lie near water. 



Eisen further supplied an illustration with his 

 diagnosis, but thus far I have found no one who has 

 discovered the worm elsewhere. Early this year I 

 took a form in the South of England which I thought 

 would prove identical therewith, Ibut some leeches 

 devoured all my specimens on the journey to the 

 north. 



