152 



NATURE 



[October 25, 191 7 



scribe eighteen species and two subspecies new to 

 science. Finally, Messrs. J. Henderson and L. E. 

 Daniels contribute a long paper, likely to interest mala- 

 cologists, on hunting Mollusca in Utah and Idaho, since 

 they record some valuable ecological observations. 



We have received from the Royal Italian Oceanographic 

 Committee a memoir (No. xxi'., 1916) by the secretary. 

 Prof. Giovanni Magrini, setting forth its objects and 

 giving a short account of its activities. The committee 

 was established in 19 10 for carrying out physico-chemical 

 and biological investigations in Italian seas and for 

 the study of the higher atmosphere. There are influ-- 

 ential provincial sub-committees at Genoa, Naples, and 

 Venice, which undertake work of especial importance 

 in their respective areas, e.g. the Venetian sub-com- 

 mittee has carried out -experiments with the object of 

 developing the fisheries off the Albanian coast. The 

 committee has, in an excellent situation at Messina, a 

 central Institute of Marine Biology, capable of accom- 

 modating eighteen workers, besides the staff, and a 

 motor-boat provided with the usual apparatus for 

 plankton and other work. In addition, the committee 

 has a well-equipped steamer 124 ft. long, with 

 accommodation for eight technical experts and 

 two assistants. During the years 1909-14 four- 

 teen cruises for physico-chemical investigations 

 were made in the Adriatic, and researches on the cur- 

 rents of that sea have also been carried out by means 

 of 685 couples of drift-bottles, set free in 19 12-14, 

 32 per cent, of which have been recovered. Six bio- 

 logical cruises were made during the years 19 12-14 

 in the neighbouring seas ; a list of the publications 

 resulting from these is given. A short account is 

 added of the Royal Italian Aerological Service. 



In the kiti dei Lincei (vol. xxvi., (i), p. 9) Dr. 

 R. Perotti describes his examination oi samples 

 of bread damaged by the attacks of fungus 

 growths which he refers to Oospora variabilis, Lind- 

 ner. In the sample submitted every hole in the bread 

 was carpeted over with a milk-white growth which 

 rendered the bread unfit for food. By experimenting 

 with cultures, the author has proved that infection takes 

 place through the leaven, and he finds that thorough 

 baking at a sufficiently high temperature, especially 

 with small loaves, prevents the growth, while incom- 

 plete cooking in a cool, damp oven^ is favourable to 

 development. Moreover, the leavea should be care- 

 fully prepared and stored, so as to avoid risk of infec- 

 tion. 



From observations made by Dr. B. Grassi and M. 

 Topi, under the direction of the Italian Ministry of 

 Agriculture, and described in the Atti dei Lincei (vol. 

 xxvi., (i), p. 5), it would appear that the phylloxera 

 of the vine has undergone considerable variation, 

 different races having developed which infect varieties 

 of vines growing in different localities. The existence 

 of such varieties had been previously noted by a 

 previous writer, who proposed the narne pervastatrix 

 for the phylloxera attacking the vines of cer- 

 tain districts. In the present experiments, which 

 date from 19 14, numerous cases are described 

 in which galls taken from one selected vine 

 failed to infect other varieties. For example, on being 

 infected with galls from Ventimiglia, the infection de- 

 veloped regularly on two varieties of vine, while on 

 three others it completely failed to develop, and some- 

 what different results were obtained with galls •from 

 Arezzano. 



An account of Hedychium coronarium growing in 

 the wild state in the States of Rio and Parana. Brazil, 



NO. 



2504, VOL. 100] 



is given in Kew Bulletin, No. 3, by the late Mr. Clay- 

 ton Beadle, whose recent death is much to be deplored. 

 Mr. Beadle had taken great interest in Hedychium as 

 a plant for paper-making, and his journey to Brazil 

 was undertaken with the object of studying the growth 

 of the plant under natural conditions. The plant grows 

 in abundance in the low-lying lands, especially near 

 Morretes, in Parana, the stems reaching a height of 

 as much as 12 ft. Mr. Beadle found it was possible 

 to make a very fair white paper from the stems grow- 

 ing in Brazil. 



The occurrence of boreal t3'pes in the southern hemi- 

 sphere is always a matter of interest to biologists study- 

 ing animal and plant distribution, and the occurrence 

 at the Cape of Good Hope of the composite genera, 

 Matricaria and Chrysanthemum, is worthy of note. 

 Six species of Matricaria and five of Chrysanthemum 

 are recorded from the Cape region by Mr. J. Hutchin- 

 son in Kew Bulletin, No. 3. Both genera belong to 

 the northern regions, Matricaria having only one 

 species in tropical Africa, while Chrysanthemum, ex- 

 cept for the Cape species, does not occur south of the 

 Canary Islands. The five species at the Cape are all 

 endemic, and one of them, with fleshy stems and 

 leaves, from Namaqualand, is here described for the 

 first time. The Matricarias are also all endemic, with 

 very restricted distribution. 



The annual report of the Agricultural Department, 

 Dominica, for 1916-17 is, as usual, a document of 

 considerable interest. Unfortunately a great deal of 

 damage by the hurricane of August 28, 1916, is re- 

 corded, and there is a long account of the steps taken 

 for the treatment of the storm-damaged lime trees, 

 some photographs of which are reproduced. Reference 

 is also made to the varietal forms of Pimenta acris, 

 the bay-oil tree. As in the case of Camphor, there 

 are two or more forms, one of which gives the valuable 

 economic product, while the other is of little value. 

 The Camphor tree, which has been planted in many of 

 our English Colonies, appears to yield oil only and no 

 solid camphor, and reference is made to this in the 

 Agricultural News of June 16, 19 17, and in other 

 periodicals. Both in the case of Pimenta and Cam- 

 phor it is scarcely possible to separate the two forms 

 on morphological characters. 



In the Annals of Botany (vol. xxxi.. No. .cxxii., 

 pp. 181-87) Dr. Spencer Pickering gives a summary 

 of his investigations of the effect of one plant on 

 another growing near it. These experiments origin- 

 ated in 1895 in his well-known observations on the 

 effect of grass on fruit-trees. Proceeding from this 

 complex case to the simplest conditions, conclusive 

 evidence of toxin production in the soil by the growing 

 plant has now been obtained. The deleterious effect of 

 one growing plant on another appears to be a general 

 phenomenon. By means chiefly of pot experiments the 

 following plants have been found susceptible to such 

 influence :— Apples, pears, plums, cherries, six kinds 

 of forest trees, mustard, tobacco, tomatoes, barlev, 

 clover, and two varieties of grasses ; whilst apple seed- 

 lings, mustard, tobacco, tomatoes, two varieties of 

 clover, and sixteen varieties of grasses have been found 

 capable of exercising toxic effects. In no case have 

 negative results been obtained. The magnitude of the 

 effect _ varies greatly, but the average effect in pot 

 experiments is placed at a reduction of roughly one- 

 half to two-thirds of the normal growth of the plants. 

 The evidence that these detrimental effects are due 

 to toxin production is regarded as conclusive. A plant 

 affects its own kind just as much as anv other kind, 

 and hence it follows that the toxin formed bv anv 



