Kxnwi.i Dt.l 



M\v. I'tli. 



diiniiiiiiioii ol pil;iiiimi hi im- <■><■ •■! < ivc-insects is alsu buiiml 

 up with .1 rcductliMi of fermonts. 



MASSKS OK WATEKWOKMS.— Professor Goorgc H. 

 Carpenter reports an interestinK case of inconvenience caused 

 by water-worms. A farm drain, six inches by four inches in 

 section, was found to be completely blocked for a distance of 

 three or four feel by a mass of minute Tubihcid worm, which 

 were identified by Mr. K. Southern as LiiniiDilriliis udckcini- 

 tiiiits Claparcde. These worms can live in water or in mud, 

 and have the habit of forming large tangled masses, which 

 accumulate slowly, and can offer great resistance to strain. 



DISCHAKGK OF CUVIERIAN ORGANS.— Mr. (,. U. 

 Mines has studied the mode of discharge of the Cuvierian 

 organs of Holothiiria nigra. They are white conical bodies, 

 expelled posteriorly when the sea-cucumber is irritated. They 

 reujain attached by their bases to the .mimal. but elongate 

 into long sticky tubes which are disconnected. L'ndischarged 

 Cuvierian organs removed from the Holothurian can be 

 made to elongate by injecting them with sea-water or other 

 fluid. The natural discharge is always preceded and accom- 

 panied by a rise in the pressure w^ithin the body. It seems, 

 then, that the elongation is due to internal fluid pressure, and 

 not to any intrinsic activity of the tubes. 



TENACITY OF LIFE IN CATERPILLARS. -While 

 the larvae of some insects, such as fleas, are delicate and 

 readily killed, it is very much the reverse with others. 

 L. Bordas finds a good example in the Potato Caterpillar 

 [Plitoriiiiaca opcrculcUa), which is notably difficult to kill. 

 He notes, for instance, that immersion in alcohol (70°) for 

 six to eight hours left them able to contract the body, and to 

 move the head and limbs and mandibles. The power of 

 resistance is referred to the structure of the respiratory 

 system (stigmata and tracheae), but one would like to have 

 more precise explanation. 



POLYD.\CTYLY. — In reporting two instances of 

 supernumerary thumbs, which are not so common as 

 supernumerary little fingers. Dr. J. D. Fiddes refers to the 

 theory or aetiology of this peculiar condition. The case 

 may be stated thus: (1) Where the extra thumb is a sixth 

 digit there is no use at all in dragging in the idea of a 

 reversion to a long-lost ancestor with more than five digits. 

 There is no evidence of there ever having been any creature 



with more than five digits. (21 There are many cases known 

 where Polydactyly has rmi in a family, generation after genera- 

 tion. .-\ tendency to a duplication of a thumb or little finger 

 seems to be sometimes hereditary. In such cases the condition 

 is often symmetrical, often involving all the four extremities, 

 and is often associated with other inborn peculiarities, ii) \ 

 case of Polydactyly cropping up without any hereditary 

 precedent for it may be due to a germinal variation similar to 

 that which started the hereditary series already referred to. 

 (4» Finally, the Polydactyly may be modificational rather than 

 variational. That is to .say it may be due to " a develop- 

 mental accident " — to an abnormal amniotic band pressing 

 upon the digital bud and splitting it. Such cases of " schisto- 

 dactyly " are asymmetrical. 



LENGTH OF ALIMENTARY CANAL AND LENGTH 

 OF BODY. — A. Magnan has made careful measurements of 

 the length of the food canal in thirty species of mammals (two 

 hundred and eighty specimens), and finds that its ratio to the 

 length of the body is least in the carnivorous forms, greatest 

 in the vegetarians, and intermediate in those that may be 

 called omnivorous. The same general statement holds true of 

 birds, and is to be interpreted as a physiological adaptation to 

 the digestibility of the various types of food. It applies not 

 merely to the length of the food canal, but to its internal 

 surface, though the patient measurer has not yet taken the villi 

 into account. 



HYBRIDISING SEA-URCHINS.— Professor E. W. Mac- 

 Bride, working at the Marine Biological Station at Millport on 

 the Clyde, has succeeded in fertilising the eggs of the common 

 heart-urchin iEchiitocardiiiiii cordatiiiii) with the sperms of 

 Echinus esciilentiis and in rearing the hybrid larvae for eight 

 or nine days. Previous workers on similar lines have, in most 

 cases, found that the hybrid larvae of sea-urchins were of the 

 maternal type, but MacBride finds in his case that the larvae 

 show paternal characters as well. The case is of great 

 interest on this account and also because the two genera are 

 so far apart. The author points out that Echinus and Echino- 

 cardinni have been distinct since the beginning of the Secondary 

 epoch, and that their common ancestor could not have lived 

 later than a period which a moderate estimate would place at 

 twenty million years ago ; yet the germ-cells of the two types 

 will commingle so as to produce a hybrid in which both 

 paternal and maternal characters are represented. 



STONYHL'RSr COLLl'.Cl' 013SKR\'.\T()KV 

 Hv FRANK C. DICXXETT. 



Thk report of this busy observatory for 1911, by Rev. W. 

 Sidgreaves, S.J.. F.R..-\.S., its Director, is just to hand. The 

 year's mean barometic pressure was only -053 inch above the 

 average of the last sixty-four years. Every monthly mean, 

 excepting November and December, was above its average, 

 January showing the highest and December the lowest of the 

 year. January had a rainfall nearly two and a half inches 

 short of its average, whilst December was over two and a 

 half inches in excess. The latter was the wettest month of 

 the year, rain falling on twenty-seven days, but it was warm, 

 the temperature being 4' -2 above its average. February was 

 another very wet month being 2-68 inches in excess of the 

 average. July had a rainfall over three inches below its 

 .iverage, receiving less than a quarter of its usual supply. July 

 was also remarkable in having bright sunshine for eighty-two 

 hours in excess of the monthly .average, and sixteen hours 

 above all previous records. The mean temperature of .August 

 was half a degree higher than that of July, and was the highest 

 on record for the month, and 4°-7 above the average. The 

 mean temperature of the year, 48"^ -6 is l°-7 above the 



average. April U)tli had a wind velocity of fifty-three miles 

 per hour, a record for .-\pril. The decrea.se in the daily spot 

 area upon the Sun. and the mean daily range of the magnetic 

 declination (in minutes of the arc), is well shown, as compared 

 with previous years. 



Year UJ06 1907 1908 1909 1910 1911 



Spot area 4-8 5-S 4-6 3-S 1-8 0-3 



Declination range... 13-9 14-7 14-1 13-5 14-5 l-'-6 



The unit of the spot area is eiinal to one-fivethousandtli 

 part of the visible disc. 



The monthly means indicate the solar minimum in 

 December. [But this may perhaps be a little premature — 

 F.C.D.j The magnetic minimum resting on daily measures, 

 distinctly points to a date later than December. 1911. Of the 

 eight comets of the year, three were under as constant 

 observation as the weather would permit, sixteen photographs 

 being taken of that of Brooks, 



