4o6 



NATURE [August i6, 1906 



as we have seen to be usually the case with nummulites ; 

 but in the other two species the size attained by the two 

 forms is approximately the same. Hence there is in them 

 no external indication of dimorphism, and it is necessary 

 to grind down the little shells to expose the initial chambers 

 in section before they can be referred to one form or the 

 other. The results of the investigation are fully set forth 

 elsewhere,' and I need only say here that on proceeding 

 in this manner with these two species, after grinding down 

 a number of examples which proved to belong to the 

 commoner megalospheric form, I came in each, as I fully 

 expected I should, on examples of the raicrospheric forms. 

 The English beds, therefore, offer no support to the view 

 that one or other of the forms of a species may occur 

 solitary. - 



On e.xamining sections of the two forms, megalospheric 

 and microspheric, in the three species, a further point of 

 interest presented itself, namely, that the megalosphere, 

 the initial chamber of the megalospheric form of 

 W. laevigattis, was much larger in proportion to the size 

 of the megalospheric shell than the megalospheres of 

 A', variolarius or A'. Orbignyi. I was, therefore, led to 

 examine the proportion in a larger number of forms, and 

 the fine series of nummulites contained in the collection 

 presented by Dr. H. B. Brady to the University of Cam- 

 bridge gave me the opportunity of doing so on ten species 

 or varieties.' 



In A', complanalus the microspheric form attains a 

 diameter of about 2 inches (51 mm.), the megalospheric 

 form a diameter of 5-0 mm. In A'', variolarius the micro- 

 spheric form has a diameter of about 1-92 mm. and the 

 megalospheric form of about i-8 mm. 



The result of careful measurement was to show that the 

 volume nf the megalosphere is, within narrow limits, pro- 

 portional to the volume of protoplasm contained, not in 

 the whole megalospheric, but in the whole microspheric 

 test. In other words, and in the light of our knowledge 

 of the life-history of the dimorphic Foraminifera, the 

 volume of each of the individual members of a brood 

 of megalospheric young is in Nummulites proportional to 

 the bulk of the protoplasm of the microspheric parent out 

 of which they are formed. In Hertwig's essav, above 

 quoted, it is pointed out (p. 30) that in functional cells 

 (not eggs) there is a definite proportion between the mass 

 of a protoplasmic body and the mass of nuclear substance 

 contained in it. If we apply tliis to the result attained for 

 Nummulites it would appear that the mass botli nf the 

 protoplasm and its contained nuclear material are in this 

 asexual mode of reproduction proportional to the whole 

 hulk of the protoplasm out of which they are formed. It 

 would appear to follow that among Nummulites the number 

 of the members of the brood in the asexual mode of repro- 

 duction ought to be approximately the same in all species. 



In the sexual mode of reproduction no such relation 

 holds, for the microsphere in A', gizehensis,'' the micro- 

 spheric form of which attains a diameter of 23-7 mm., is 

 hardly larger than that of A^. variolarius. \n which the 

 diameter of this form is, as we have seen, 1-92 mm. 



1 Paper by the author "On Ihe Dimnrphism of lh» English Species of 

 Nummulites and the Size of the Megalosphere in relation to that of the 

 Microspheric and Megalospheric Tests in this Genus." /',vc. Koj. i>,., 

 vol. R. Ixxvi., 1905, p. 298. 



2 When the two forms are of differpnt sizes, and the materials of a bed 

 have been rearranged hy currents, they may. of course, he difierently 

 distrib'ited. 



'■'■ The species (or. on the old view, pairs of species) thus examined are :— 

 N. complaiiatus, LamV.. megalospheric form '' N.TchihattlKjn.A' \rch: 

 N. per/aratits{A^'h\or\^h.') ,. ,, ^' N. Luca^ann^ Defr " 



^V. G/=<-;/i:«i,i(Forsk.) ,, ,, " N. tii,-'ii/,i,;',s 



(Menegh.)' 

 h . fcr/oratus. \3.\. obrsKS .. ,. '^ X. LuLasaiius. ^xr. obio 



Ut„i. d. I. H." 

 N. laevigatns(^x\:,z.) ,, ,, " Znw/nr.Xv, d Arch." 



/4s«V/«a f.v/wic»,v (Sow.) ., '-.-I. ;«,!,„///„,'« (d Arch.)" 



N. bmrritzensis. &• kxA. ,, '' K. Gzu-ttardl, d: kmh." 



A'. rf«<r,i)-*;;/;« (Schlot.) .. ., " N. si(b-discorblims, i. \. 



N. OrHi„vi (Gal.), var. 

 clegans(%av.:\ 

 and 

 N. varioiarhis (Lamk.) n 



^ I h.ive been unable to r 

 owing to the cavities of the 

 calcite, and their outlines obi 



H.' 



" i\'. locn.'ntelc'isis. d. I. H. 

 and \. d. Br., var. 

 cie^atis. .Sow.'' 

 crospheric ,, " A'. //,■/•«■/■/, d'Arch. and 



easui-e the microsphere in the Ipr^er species 

 chambers in my specimens being filled with 



NO. 1920, VOL. 74] 



In addition to the structural and other characters, bind- 

 ing the members of " a pair " of Nummulites together, 

 which led De la Harpe to conclude that they belong to the 

 same zoological group, we may now therefore add another 

 — the ratio in volume between the megalosphere of one 

 and the protoplasmic contents of the whole shell of the 

 other. 



It would be interesting to find how far this proportion 

 holds good in other genera of Foraminifera. I do not 

 know of any phenomenon precisely comparable with it 

 elsewhere, but the result is so definite that it would appear 

 to be the expression of a general principle. 



In conclusion, I may call attention to the difference 

 presented by the species of the genus Nummulites in the 

 relative length of life (as indicated by size) of their sexually 

 and asexually produced forms. In A', variolarius the life- 

 cycle is apparently equally divided between the two, while 

 in N. complanatus the small megalospheric form (" N. 

 TchihatchefH ") is almost as much dwarfed by the gigantic 

 microspheric form as, in the life-history of a fern, the 

 prothallus is by a member of the sporophytic generation. 



UNIVERSITY AND EDUCATION.iL 

 INTELLIGENCE. 

 Dr. O. W. Rich.^rdsox, of Trinity College, Cambridge, 

 has been appointed to the chair of physics in the Uni- 

 versity of Princeton, New Jersey. 



Science announces the gift of 10,000/. to Yale University 

 by Mr. E. Milner, of Plainfield, Conn. The interest is to 

 be used for the education of some resident of Plainfield. 



Mr. E. B. H.\rt has been elected professor of agri- 

 cultural chemistry, and chemist, in connection with the 

 agricultural experiment station of the University of 

 Wisconsin. 



The King has approved of the appointment of Admiral 

 -Sir -'Arthur Dalrymple Fanshawe, K.C.B., as president of 

 the Roval Naval College. Greenwich, in succession to Sir 

 Robert Harris, K.C.B., K.C.M.G. 



Sir WiLLi.iM Thomson has been appointed by the Chief 

 Secretary for Ireland inspector of schools of anatomy for 

 the provinces of Connaught, Ulster, and Leinster, in the 

 place of Dr. W. J. Martin, deceased. 



At Lehigh University Messrs. P. A. Lambert and A. E. 

 Meake have been appointed professors of mathematics,, 

 and at the same university ^Ir. J. D. Irving has been 

 elected to a professorship in geology. 



Dr. D. Noel P.atox, superintendent of the laboratory 

 of the Royal College of Physicians, Edinburgh, has been 

 appointed regius professor of physiology in the University 

 of Glasgow in succession to Prof. J. G. M'Kendrick, 

 F.R.S., resigned. 



Prof. Wm. H. Hobbs, of the University of Wisconsin, 

 has been appointed successor to the late Prof. Israel C. 

 Russell in the professorship of geology in the University 

 of Michigan. Prof. Hobbs, who is at present in Europe, 

 will leave for .\merica to take up his new duties on 

 August 25. 



The eleventh annual examination in the science and 

 practice of dairying for the national diploma of the 

 National Agricultural Examination Board will take place 

 at the Midland Agricultural and Dairy College, Kingston, 

 Derby, from September 24-27 for English students, and 

 at the Dairy School, Kilmarnock, from October 1-5 for 

 Scottish students. .All applications must be sent in by, at 

 latest, August 31. The subjects of exainination are the 

 general management of a dairy farm, the manageinent of 

 a dairy, chemistry and bacteriology, practical skill in dairy 

 work, and capacity for imparting instructions to others. 

 Forms of entry and copies of the regulations may be 

 obtained from the secretary of the Royal Agricultural 

 Society, or from the secretary of the Highland and Agri- 

 cultural Society. 



