HA RD U'ICKE'S SCIENCE- G OSSIP. 



37 



33 fi, reaching occasionally 35 j", but not exceeding 

 that limit. But, fortunately, Plow-right published 

 specimens of this species in his " Sphseriacei Brit- 

 annici," ii. No. 49. These I have not seen, but 

 Winter has given the measurement of sporidia, from 

 these specimens as 28-32 /* X 7 p, thus agreeing 

 exactly with mine. 



We conclude, therefore, that the length of the 

 sporidia, given by the original finders of the species, is 

 too great. Tiie difference may appear, to outsiders, 

 very little ; but it is found by experience that in the 

 majority of cases, the size of the sporidia of sphoeria- 

 ceous fungi is remarkably constant, and I have a 

 reason for insisting on this point, as will appear from 

 what follows. 



My specimens were found on the nettle ; L. sex- 

 nitclcatum, referred to above, also occurred on the 

 nettle. Moreover, in Cooke's article on "Old 

 Nettle-Stems and their Micro-fungi," the latter is 

 stated to occur on stems "far advanced in decay," 

 so as to be "tender and friable," as mine did. The 

 chief difference between the alleged species is in the 

 sporidia ; those of sex-nucleatum, which are given as 

 35 fx long, are said to be shorter than those of angus- 

 tilabrum, but the measurements quoted above dispose 

 of this difference. Again, the sporidia of sex-nu- 

 cleatum are, as the name implies, six-nucleate, each 

 "nucleus" occupying a cell. By a "nucleus," here 

 is meant an oily drop of much higher refractive index 

 than the other cell contents. These objects, by-the- 

 bye, are now called " guttulse," since they have nothing 

 in common with a true cell-nucleus. The sporidia of 

 angustilabrum, on the contrary, are said to contain 

 " two or three nuclei " in each half, and apparently 

 have rarely been seen with more than a central 

 septum, although said to be "probably 4-6-celled 

 when mature." 



Now, in Fig. 34, I have given a group of sporidia 

 taken from a single perithecium of my specimens, 

 and in Fig. 33, tracings from Cooke's drawings of 

 the sporidia of the two species. By the comparison 

 of these, it will be seen that the extreme forms of 

 Fig. 33 are connected by intermediate links. When 

 several guttulre occur in a row, it is easy by manipula- 

 tion of the light to produce a false appearance of 

 septa between them, as at b (Fig. 34). This is a 

 mere illusion of diffraction. I satisfied myself that 

 none of the sporidia in my specimens were more 

 than uniseptate. The earlier observers seem not 

 to have been always on their guard against such 

 illusions. 



The sporidia of angustilabrum are further said to 

 terminate in hyaline conical appendages at each end, 

 which are wanting in sex-nucleatum. My specimens 

 sometimes had, but oftener had not, these appendages. 

 In Cooke's figure of the sporidia of angustilabrum 

 in his article on " Lophiostoma," he represents a 

 distinct enveloping membrane, of which I could see 

 no trace. Winter also describes this ; but Saccardo, 



who figures the sporidia of the same species ill 

 his "Fungi Italici," No. 238, says nothing of its- 

 existence. I conclude that this is not always present, 

 which is very likely, for it is not in any case a mem- 

 brane, but merely the outline of some mucilaginous 

 matter surrounding the sporidium. 



I think, therefore, that the last remnant of a 

 difference disappears, and L. sex-nucleatum must be 

 considered as merely a synonym, representing pro- 

 bably the most perfect state, of L. angustilabrum. 

 This is what will, as I have previously hinted, befall 

 many of the new species described in these days, as, 

 indeed, it has done in the past. The true rule on 

 this point I have laid down before. It is the duty of 

 anyone who discovers a form of life which he cannot 

 identify with any previously described, to give it a 

 name, and append to the name a careful description ; 

 but it is equally his duty, when its identity with some 

 previously known form is demonstrated by the dis- 

 covery of facts which he was ignorant of, cheerfully 

 to allow them to be united under one name, or to 

 unite them so himself. 



W. B. Grove, B.A. 



NOTES ON THE COTTON FIBRE. 



By Walter Henshall. 



II. 



HAVING described the general character of the 

 cotton hair and its method of growth, we 

 must now pass on to its structure and composition. 



From treatment with various reagents, particularly 

 an ammoniacal solution of oxide of copper, the cotton 

 hair has been found to consist of four parts, quite 

 distinct from each other : 1st, the outside membrane, 

 which is insoluble in the copper liquid ; 2nd, the 

 cellulose, which occupies by far the greatest portion 

 of the fibre, and round which there appears to be 

 wrapped from end to end (3rd) spiral fibre ; 4th, an 

 insoluble matter occupying the core of the cotton 

 hair, which resembles the shrivelled matter in the 

 interior of quills. This solution (also known as 

 Schweitzer's solution) has the power of dissolving 

 cellulose, and it is most interesting to watch its action 

 on the cotton fibre under the microscope. Before 

 dissolving, the cellulose swells out enormously, 

 dilating the outside membrane, and stretching out the 

 spiral fibre, which is not so elastic as the outer 

 membrane. This causes it to break in many places, 

 the cellulose forming bead-like swellings where the 

 spiral has broken away. 



The action which other reagents have on cotton is- 

 also interesting. Caustic soda has a most peculiar 

 effect on the fibre. When cotton is soaked in a 

 solution of caustic soda, the fibres increase very much 

 in diameter, and besides becoming fuller, the soda 

 leaves them much stronger. It has also been found 



