556 



NA TURE 



[September 26, 1907 



perturbations were more intense on the meridian passage 

 of a region which, having been active before, was increas- 

 ing in activity. 



Three excellent drawings of the great January to April 

 (1905) sun-spot made by Prof. Mascari are reproduced in 

 No. 7, vol. x.\.\vi., of the Uemorie della Societa degli 

 Speiiroscopisti lialiani. 



The Juvisv Observ.atory.— An interesting description, 

 illustrated with photographs, of the Juvisv Observatorv 

 appears in the August and September issues of the BullcUn 

 de la SocUte astronomique de France. The observatorv 

 was founded in 1883 by M. Flammarion, and is principall'v 

 engaged on planetary observations. 



BOTANY AT THE BRITISH 

 ASSOCIATION. 

 ' j 'HE time of Section K was considerably occupied in 

 joint meetings with other sections. Thus there was 

 a joint discussion with Section D on " The Physical Basis 

 of Heredity," of which an account will be found in 

 " Zoology at the British Association " (N.\ture, September 

 '9. P- 530). and another with Sections D and L on " The 

 Teaching of Biology in Schools," which is described in 

 " Education at the British Association " (Nature, 

 September 12, p. 505). 



A third joint meeting was held, with Sections C, D, 

 and E, to hear an address by Prof. Conwentz, the Prussian 

 State Commissioner for " Naturdenkmalpflege," on "The 

 Preservation of Natural Monuments." Prof. Conwentz 

 explained that the phrase " natural monuments " was 

 new in Germany as well as in England, but we should 

 recognise that there could be monuments of nature as well 

 as of art. The constant inroads of cultivation and of 

 industrial undertakings have led, and are leading, 

 especially in countries with crowded populations, to the 

 disappearance of scientifically interesting and even unique 

 natural objects and types of scenery. A widespread feel- 

 ing has arisen that as much as possible should be done 

 to prevent such destruction, and this has recently led, not 

 only to much local effort directed towards this end, but 

 in Prussia to the institution of a special State depart- 

 ment under the Minister of Education for the purpose of 

 directing and coordinating such efforts. This department 

 (of which the lecturer is the head) has no funds allotted 

 to it for the actual purchase of land bearing natural 

 monuments, nor is it considered that purchase is the right 

 procedure except in special cases. The aim is rather to 

 get private owners interested in the natural monuments 

 on their property, and to induce them to be responsible 

 for their safeguarding and preservation. In the case of 

 Government land, the Forestry Department cooperates 

 by making regulations prohibiting the felling of unique 

 trees, the total clearance of particular types of woodland, 

 &c. Prof. Conwentz's department is prepared to initiate 

 all effort of this kind in Prussia. Its activity has already, 

 during the single year of its existence, met with consider- 

 able success. Many areas of primitive marsh and water, 

 heath and woodland, often containing rare and interesting 

 characteristic species of animals and plants, have been 

 saved from destruction, and arrangements made for their 

 permanent preservation. The necessary work falls under 

 three heads : — first, the cataloguing of the natural monu- 

 ments of the country ; secondly, the mapping and scientific 

 description of such monuments; and thirdly, the under- 

 taking of appropriate means for their preservation. 



Prof. Conwentz directed attention to the numerous 

 organisations in this country the work of which tends 

 towards this general object, but pointed out that none of 

 them have precisely the same ends in view as his Prussian 

 department. He particularlv mentioned the Commons 

 Preservation Society, the Kyrle Societv. the National Trust 

 for the Preservation of Places of Historic Interest and 

 Natural Beauty, and the Central Committee for the Survev 

 and Study of British Vegetation. He suggested that the 

 Ust-named organisation might add the preservation of 

 British vecctalion to its objects, and also that efforts in 

 this direction might be helped bv the British Association. 

 He pointed out that love for and care of the characteristic 

 natural scenery of the homeland was one aspect of true 

 NO. 1978, VOL. 76] 



patriotism, and should act as a check on the purely 

 materialistic development of modern civilisation. The 

 lecture was illustrated by a beautiful series of lantern- 

 slides showing types of protected scenery in Germany, and 

 also of many British examples of a similar kind. 



Discussion on the Cytology of Reproduction in the 

 Higher Fungi. 

 This occupied most of Monday morning, August 5. 

 Three papers were read, and were loUowed by a discussion. 

 In the first paper Miss Eraser and Jliss Chambers 

 described the development of the ascocarp in Aspergillus 

 {Eurotium) herbariorum. The archicarp consists of a 

 unicellular trichogyne, a unicellular ascogonium, and 

 septate stalk. An antheridium, divided into a stalk and 

 antheridial cell, is present, and usually fuses with thi 

 trichogyne ; both structures are ca>nocytic. After normal 

 fertilisation or its equivalent, the ascogonium becomes 

 septate and produces ascogenous hypha;. A sheath i: 

 developed, and finally asci are formed. In these, nuclear 

 fusion takes place, and three divisions follow, giving rise 

 to the nuclei of the eight spores. 



The authors regarded the genus .Aspergillus as primitive, 

 and related its archicarp to that of other groups of 

 .Ascomycetes. They pointed out that the male organ 

 closely resembles the antheridium of discomycetous forms ; 

 on the other hand, if the antheridial cell, instead of fusing 

 with a neighbouring archicarp, were set free from its 

 parent hypha, it would scarcely differ from the spermatium 

 of the Pyrenomycetes. They held, with Wolfe, that a 

 similar development had taken place among the Floridece, 

 and regarded the .Ascomycetes as a monophyletic group. 



Miss Wclsford's paper dealt with fertilisation in 

 Ascobolus furfiiraceus. She confirmed Harper's statement 

 that the archicarp, or scolecite, originates as a row of 

 uninucleate cells. These subsequently become multi- 

 nucleate, and one increases in size and gives rise to 

 ascogenous hypha;. Nuclei migrate into this cell and 

 undergo fusion before passing into its branches. Miss 

 VVelsford regarded this process as a form of reduced 

 fertilisation, and suggested two interpretations — either 

 (i) the scolecite is a multicellular female organ and the 

 fusions are those of female nuclei in pairs, or (2) the 

 ascogenous cell only is female, the other cells of the 

 scolecite being vegetative and representing a funciionless 

 trichogyne and stalk ; in this case fertilisation probably 

 ctjnsists of the union of a female and a vegetative nucleus. 

 In the third paper Miss Eraser gave an account of the 

 cytologv of Uumaria ruiilans. In this species sexual 

 organs are not developed, but a reduced form of fertilisa- 

 tion obtains, the nuclei of the vegetative mycelium fusing 

 in pairs. -Asci are developed from hyphse which contain 

 fusion nuclei ; these show sixteen chromosomes, the sporo- 

 phytic number, in their mitoses. In each ascus three 

 nuclear divisions take place ; the first is heterotype, the 

 chromosomes dividing transversely , and the second homo- 

 type. These bring about a reduction, related here, as in 

 all other investigated organisms, to normal or reduced 

 fertilisation. During the prophases of the heterotype 

 division, a second nuclear fusion occurs ; Miss Eraser 

 suggested a mechanical explanation for this process, and 

 showed that it was occasionally omitted. The sixteen 

 chromosomes which are present throughout the meiotic 

 phase represented the reduced number for two nuclei. 

 The fusion in the ascus is compensated by a peculiar 

 process of reduction taking place in the third division, and 

 termed by Miss Fraser hrachymeiosis. Sixteen chromo- 

 somes are formed from the spireme, and eight p.iss -with- 

 out fission to each daughter nucleus. The reduced number 

 for one nucleus thirs appears. 



The author considered that this process probably 

 occurred in connection with other asexual fusions also. 

 She related her observations on Uumaria rutilans to the 

 facts described for Phyllactinia (Harper, 1905) and other 

 .Ascomycetes. In conclusion, she pointed out the close 

 analogy between the two fusions in the life-history of 

 Uumaria, and suggested that the type of compensating 

 reduction (whether meiotic or brachymeiotic) might be use- 

 fullv employed to differentiate between sexual and asexual 

 fusions. 



The discussion was opened by Prof. Farmer, who agreed 



