136 



HARD WICKE ' S S CIENCE- G SSIF, 



below the stigma, it is clear that the loosening of the 

 pollen would be useless as a help to fertilisation, and 

 as above stated these insects seem but seldom to 

 attack this form, although occasionally found on it. 

 4. They chiefly frequent the smaller-sized flowers, 

 which it is evident would be more dependent upon 

 self-fertilisation since the bees and other cross-ferti- 

 lising agents are attracted by the size of the flower, 

 and would be more likely to visit and consequently 

 to cross-fertilise the larger-sized flowers. — T. IV. B. 



The Crust on Teeth. — In consequence of the 

 inquiry of E. J. W. in Science-Gossip for April 

 last as to what are the rod-like filaments found in the 

 substance which accumulates around the bases of the 

 teeth, I allowed my teeth to remain unbrushed for 

 three or four days, and then examined the accu- 

 mulated matter. There was an abundance of the 

 filaments, which I have no doubt are some species of 

 Oidium, being very similar to, if not identical with 

 Oidiuni albicans found on the mucous membrane of the 

 mouth in adults and children suftering from aphthre 

 (known also as thrush, white mouth, and Le INIuguet). 

 I found also great numbers of spirillce, longer than I 

 ever saw before, bacteria, which, by the way, appear 

 to be everj'where, and, to my great surprise, great 

 numbers of an infusorian of which I send you a 

 fairly representative sketch, and a few of another 

 shape. They were very lively, each contained a 

 vacuole and granular matter, and they were capable 

 of changing their forms in order to accommodate them- 

 selves to the space in which they had to move — in fact, 

 were exactly similar to those found about plants 

 growing in stagnant water but for the absence of 

 coloured contents. They were easily made out with 

 a one-fifth objective and No. i and 2 eye-piece. It 

 would be very interesting to know more about them, 

 and I write this in the hope that some microscopist 

 with more time than I can command may take 

 the subject in hand, and if possible, work it out. — 

 D. Bradley, L.R.C.P. Edin. d-r. 



Preserving ZoorviiTES.— While in Dublin about 

 a month ago, I gathered some Sertulaiia covered 

 with Campanularia and Carchesium. I have, on 

 previous visits to the seaside, tried to preserve them 

 for the microscope with the tentacles exserted, but 

 failed. This time I had another try, but, as they did 

 not exsert themselves well, I did not take much notice 

 of them, but killed them with spirit, and dropped 

 them into pure glycerine, as they are well preserved. 

 I intend the ne.xt time I am at the seaside (in a few 

 weeks), to place some in a small tube, and when 

 exserted, kill them with spirit, then pour off the 

 spirit and water and refill with pure glycerine, till I 

 have time and opportunity of mounting them. The 

 tentacles of the Sertularia or Campanularia, also the 

 Carchesium, are preserved in that which I have by 

 me. — E. ]V. Bnrzcss. 



Nomenclature. —I think it would be much more 

 edifying to observers at Microscopical soirees and 

 meetings, if exhibitors followed the example set by 

 the President of the Quekett Club at University 

 College on Friday the 29th of April, that is, that 

 after placing the name of the object he had under 

 the microscope, on a card he gave the 



Class ...... 



Order 



Genus ...... 



I may mention he added a drawing of the object, but 

 this might be expecting too much from most people. 

 I am quite sure that many people at soirees do not 

 know whether they are looking at animal, vege- 

 table, or mineral ; they see a long name, say " How 

 pretty!" and pass on. I think that exhibitors- 

 should give more information for " casuals.'' — H. R., 

 Warrington. 



ZOOLOGY. 



The Physiological Unity of Plants and 

 Animals. — Professor Boulger, F.L.S., F.G.S., 

 recently delivered a lecture on the above subject 

 before the Sunday Lecture Society. Professor 

 Boulger showed the parallelisms existing between 

 plants and animals, and how plants and animals are 

 identical in their ultimate chemical constituents. 

 Professor Boulger directed attention to the striking 

 analogies between the higher forms of both groups, 

 showing how closely related are the three main 

 physiological functions, nutrition, relation and repro- 

 duction. The function of respiration, subsidiary 

 to nutrition, is absolutely identical in both groups, 

 i.e. oxygen is inhaled and carbonic acid exhaled, 

 the ordinary assimilation of carbon from the 

 atmospheric carbonic acid, not being respiration 

 in the physiological sense of that word. The 

 function of nutrition at first sight seems to be 

 entirely contrary ; in the two groups, animals being 

 unable to build up the complex compound of which 

 they consist, from inorganic materials. This con- 

 trast does not, however, hold universally. Fungi, and 

 all parasitic plants depend, in a great measure, on 

 food already assimilated, and the other plants termed 

 carnivorous may in many cases be said to have true 

 digestive organs, which bear comparison with those 

 of the higher animals. The functions of relation are 

 motion, sensation, and nervosity. Some few animals 

 lose the power of motion from place to place, a power 

 only possessed by the lowest plants. The higher 

 plants, however, in many cases possess as much 

 power of relative power, as many animals, such being 

 circumnutation, the irritability of stamens, the 

 revolving motion of tendrils. Motion is also effected 

 by pseudopodia in the myxomycetes and other thallo- 

 phytes, as much as in the lowest animals, and by 



