342 



NA TURE 



ypch. 7, 1884 



and 5 treat of the Florides, which are concluded in the 

 sixth part. Then follow the Phaeophyceae ; but before 

 touching on these, a few points relative to some of the 

 Florideae call for observation. 



M. Hauck tells us that in Gelidium the cystocarps 

 are of two kinds — (1) those in which the placenta is basal, 

 and have consequently only one series of gemmidia ; 

 (2) those in which the placenta is central, on both sides 

 of which the gemmidia are placed. M. Hauck does not 

 seem to be aware that the former were long ago separated 

 by Dr. Agardh from Gelidium^ under the name of Ptero- 

 cladia, the typical species of which is Pt. lucida, a very 

 common alga in the Southern Ocean. The Gelidiiiiii 

 capillaccum, described at p. 190, is a true Pterocladia, and 

 has been described as such by M. Bornet under the name 

 of Pt. tapillacca. M. Hauck mentions this name among 

 the synonyms of G. capillaceum, and at p. 191, fig. 82, 

 he gives us copies of M. Bornet's figures of the cystocarps 

 of this plant, and also of Gelidium ; thus showing the 

 characteristic differences between the two algse ; it is 

 therefore surprising to find that M. Hauck still retains 

 the old name of the plant, and places it under the genus 

 GeUdium. 



The cystocarpic fruit of Dasya fitnicea, apparently 

 unknown in the Adriatic, was found on our southern 

 coast as long ago as 1S59. Before that time a specimen 

 bearing cystocarps was collected by Miss Catlow in 

 Jersey, and Dr. Harvey gave to it the provisional name 

 of Dasya catloivoicc. There is considerable difiference in 

 the aspect of the plants which bear cystocarps and those 

 which bear stichidia ; so much so, that they have been 

 taken for distinct species. British specimens of this 

 plant are much larger than those of the Adriatic. 



M. Hauck describes the tetraspores oi Mclobesia coral- 

 Una as " zueitheilig," and he refers to Solms' " Coral- 

 linenalgen des Golfes von Neapel," Table III., fig. 23. 

 Now, on turning to this figure in the work of Graf Solms, 

 it will be seen that the tetraspores are 4-partite. It is 

 true that they have been described by MM. Crouan and 

 Areschoug as dipartite, but, according to the observa- 

 tions of M. Roscnoff in his very interesting " Recherches 

 sur les Melobcsices," p. 45, there seems good reason to 

 believe that, although tetraspores are often found divided 

 into two parts only, the complete number is four. 



With regard to M. iiiacrocaipa, M. Hauck is apparently 

 right in uniting itvvith M. pits/u/a/a, and also in consider- 

 ing J/, corticifonnis as a synonym of M. mevibraiiacta. 



In a former number of his work, M. Hauck had stated 

 that the tetraspores of Nemaleon were unknown. They 

 had, however, been described by Dr. Agardh in " Sp. 

 Gen. et Ord. Algarum," vol. ii. p. 417, and again in the 

 " Epicrisis," p. 507 ; but the author did not, in either 

 work, state in which species he had found them. Some 

 uncertainty, therefore, existed on this point ; and Thuret 

 was of opinion that up to his time there had been no 

 trustworthy record of the discovery of the tetraspoies of 

 Nemaleon. It would have been easy to solve the doubt 

 by an appeal to Dr. Agardh, who is always ready and 

 willing to impart information, but no one seems to have 

 thought of adopting this course. The writer is glad to 

 be able to mention, on the authority of Dr. Agardh, that 

 he (Dr. Agardh) found tetraspores on a plant of A'ci/ia- 

 leon iniiltifidtim from Copenhagen, but he had met with 

 them only once. It is hoped that this statement will 

 finally settle the question. 



The description of the second division of the marine 

 algK, Phaaophycew, is begun at p. 282 with the Fucoidea:; 

 these are followed by the Dictyotea;, and after these fol- 

 low the Pha;ozooaporea'. Each order is preceded by a 

 careful description of the structure and fructification of 

 the plants included in it, and an enumeration of the 

 genera ; in the case of the Phreozoosporea?, a short dia- 

 gnosis of each family is inserted. We are glad to see, 

 from the long list of synonyms appended to the descrip- 



tion of many plants, that M. Hauck has greatly dimin- 

 ished the number of species, especially of those from the 

 Adriatic. 



British algologists will find in the later numbers of this 

 work, as well as in those which preceded them, much 

 that is interesting and instructive. The succeeding num- 

 bers will be welcome. It is hoped that they will be fol- 

 lowed by a good index, which will add very much to the 

 value of the work. Mary P. Merrifield 



METEOROLOGICAL OBSERVATIONS FROM 



BEN NEVIS 

 A WEATHER REPORT from the Ben Nevis Ob- 

 -^*- scrvatory is now published daily, which gives the 

 observations made at 9 a.m. and 9 p.m., these being the 

 hours adopted by the Meteorological Societies of the 

 Briti•^h Islands, to which are added the highest and lowest 

 temperatures, the amount of rain and snow in all cases 

 where it is possible to measure it, the height of the snow 

 on the plateau, measured by the snow gauge, the hours of 

 sunshine, taken directly from the sunshine recorder, and 

 the quantity of ozone, droughts, changes of wind, auroras, 

 glories, halos, electrical and other phenomena, recorded 

 as they occur. The record is strictly one of observations, 

 and as these are made at the usual observing-hours, 

 British meteorologists and all persons interested in the 

 weather are thus afforded the means of comparing their 

 own observations with those made at Ben Nevis Observa- 

 tory, which is by far the most valuable high-level station 

 we possess, as furnishing data of the first importance in 

 the study of the weather changes of Europe. In the 

 winter climate of the Ben, the problem of hygrometric 

 observation is beset with formidable difficulties. With a 

 view to the practical solution of these it is part of the 

 winters programme that Mr. Omond conduct a series of 

 investigations with a hygrometer of a novel description 

 specially designed by Prof. Chrystal for the purpose. In 

 the meantime, and until the problem be solved, the word 

 "Sat," meaning saturation, is entered in the wet bulb 

 column in all cases when the wet does not read lower 

 than the dry bulb, it being evident that in such cases the 

 air is all but, if not altogether, saturated. Indeed, a 

 saturated atmosphere at all temperatures may be almost 

 regarded as a persistent feature in the climatology of the 

 Ben. Occasionally, how-ever, as recently happened about 

 Christmas and the New Year, a sudden change sets in, the 

 clouds clear away, the sun blazes out in a sky of mar- 

 vellous clearness, and a dryness of air comes on such as 

 is rarely if ever experienced at lower levels. In these 

 circumstances the dry and wet bulb readings separate 

 to a degree so extraordinary that Glaisher's tables are no 

 longer of any use in calculating the humidities of the air. 

 As the periods of sudden and intense dryness of the 

 atmosphere are intimately connected w-ith the anti-cyclonic 

 systems prevailing at the time in north-western Europe, 

 it is not improbable that a careful record and study of 

 them will lead to a more exact forecasting of some of 

 our most important weather changes. 



By and by the observations, combined with those made 

 by Mr. Livingstone at the low-level station at Fort William, 

 will furnish the data for ascertaining what is the normal 

 distribution of pressure, temperature, and humidity in 

 the stratum of the atmosphere between the top of Ben 

 Nevis and the level of the sea at its base. These being 

 once determined, all deviations therefrom, whenever 

 occurring, will be readily seen. When the departures 

 from the normals to subsequent changes of weather have 

 been further investigated and their relations more accu- 

 rately determined, the h'gh expectations formed regarding 

 the part to be played by the high-level station on Ben 

 Nevis in contributing important data towards the fore- 

 casting of the weather of the British Islands will doubt- 

 less be realised. It must not, however, be forgotten that 



