50 



SCIENCE. 



[Vol. XI. No. 260 



eral interpretation, the difference would have been only two or three 

 per cent. 



I am very glad to know that Mr. Clayton verifies his predictions 

 of three elements by only two of them, and this gives us an interest- 

 ing verification of the predictions given in my first letter. If we 

 count ' rain ' = .01 of an inch or more, and apply this to Mr. Clay- 

 ton's predictions, (i), we shall find that they verify 80 per cent ; ap- 

 plying to mine, (2), 96 per cent. But Mr. Clayton's predictions 

 were not made to be verified by this rule, so we must fall back on 

 his official figures, which are 85 per cent. 



If any thing has been brought out most clearly by this discussion, 

 it is the absolute need of a thorough examination of the method of 

 prediction in each case ; and if a comparison is to be instituted, it 

 should only be after a careful formulation of a method which shall 

 give a fair test of the nearness of the prediction to the actual 

 weather experienced, taking into account as far as possible the 

 language used in each prediction. I know it to be a fact that a 

 person may give the same prediction for a place in two different 

 terms, and a seeming application of the same rules to both will give 

 a difference of more than 35 per cent in the two verifications. 



H. A. Hazen. 



Washington, D.C., Jan. 20. 



Children's Development. 



Apropos of the letter of ' G.' on children's development, in 

 Sa'ence ol J a.n. 13, I was led to make the following contribution. 

 When my little daughter was eighteen months old, I wrote down 

 her vocabulary, as far as was possible, a number of days being 

 spent in the process, so that it may be assumed that it is nearly 

 complete. The total number of words is four hundred and sixty- 

 nine, divided as follows : — 



Common nouns 



Proper nouns (mostly names of persons) . . . 

 Adjectives (including pronouns and articles) 



Adverbs 



Prepositions 



Interjections 



Conjunctions 



48.5? 

 6.6^ 



23.2^ 



These were all words used by the child spontaneously, and in ap- 

 proximately their correct signification. Only one part of a verb is 

 counted, unless the verbal stems of the different parts are distinct ; 

 plurals are not separately counted ; and virords used both as nouns 

 and verbs are counted only once. The percentages are not mate- 

 rially different from those in the case cited by ' G.,' but further con- 

 tributions on this point seem desirable. J. L. H. 

 Louisville, Ky., Jan. i8. 



Sections of Fossils. 



Mr. Foerste, in No. 258 of Science, quotes from letters from 

 Professor Prestwich and Dr. Geikie in regard to sections of Bryozoa. 

 In referring to these authors in No. 250 of Science, I did so simply 

 to call attention to what they say in regard to rock-sections in gen- 

 eral, not Bryozoa in particular. It is not worth while to say more 

 upon this point. In regard to my reference to Dr. Nicholson's 

 work, I never inferred " that Professor Nicholson does not be- 

 lieve in the use of these microscopic sections," but that he 

 stated in numerous places in both his volumes on fossil corals 

 that in many cases it is not possible to separate species on internal 

 structure, so recourse is had to external features ; and from this 

 fact I contend that the internal structure of these organisms is not 

 sufficient to separate species. The old school, if it may be so called, 

 as opposed to the new, believe that internal characters are often 

 misleading, and that external features may more safely be fol- 

 lowed. Joseph F. James. 



Miami University, Oxford, O., Jan. i6. 



The Influence of Forests upon Rainfall and Climate. 



In closing his valuable and interesting article in your paper of 

 Jan. 6, entitled ' Do Forests influence Rainfall .' ' Mr. Henry Gan- 

 nett says, " With these results in view, it seems idle to discuss 

 further the influence of forests upon rainfall from the economic 

 point of view, as it is evidently too slight to be of the least practical 

 importance." 



Aside from the beneficial influence of forests in the retention and 

 saving of the water which falls, may it not be that there is an effect 

 of the forest upon climatic extremes of heat and cold ? This is well 

 shown, I think, by the experience of western Michigan. During 

 the early years of the settlement of the country, before the forests 

 were destroyed, all the delicate fruits of temperate climates were 

 successfully grown. 



Since the forests are nearly gone, the tender varieties of peaches 

 can no longer be raised, except in a few favored localities, on ac- 

 count of extreme winter cold ; and the heat of our summers has 

 been of late years as extreme as the cold of our winters. 



H. D. POST. 

 Holland, Mich., Jan. 9. 



Is there a Venomous Lizard ? 



In connection with the inquiry in Science of Jan. 13, as to the 

 existence of a poisonous lizard {Heloderma), my own observations 

 would corroborate the negative answer of your correspondent. I 

 have had in my laboratory for five years a living specimen of the 

 Gila monster {Heloderina suspecticm), and during a portion of this 

 time two specimens, both in healthy vigorous condition. In No- 

 vember, 1883, I presented a communication to the Kansas Acad- 

 emy of Science, maintaining that this species is not venomous. I 

 have repeatedly placed young kittens in the same cage with these 

 reptiles, and have allowed them to remain together for a week at a 

 time. During these times the kittens were frequently bitten fero- 

 ciously by the lizards, but with no worse result than the temporary 

 swelling of the part bitten from the mechanical effect of the power- 

 ful pressure. This was at first surprising to me, as intelligent 

 miners in New Mexico had often informed me that the mere breath 

 of this lizard was fatal to man. F. H. SNOW. 



Lawrence, Kan., Jan. ig. 



Queries. 



24. Silver Dollar in a Potato. — Is there any likelihood 

 of the truth of the following story found in a recent New York 

 paper.' On Friday last a young woman was engaged in boiling 

 some potatoes. She tested nearly all of the Irish apples, and 

 found that they had been cooked to the proper consistency save 

 one. This particular ' spud ' remained as hard as adamant, and, 

 although she allowed it to boil for fifteen minutes longer than the 

 others, it showed no signs of yielding. At last she succeeded in 

 splitting the vegetable open, and in the centre she found a silver 

 dollar with the date of 1886. The heart of the ' spud ' was colored 

 a blackish brown, but the outside presented a normal appearance. 

 The silver dollar was black as ink. 



22. Wasp-Stings. — Bumble-bees and honey-bees, as well as 

 wasps, may be safely taken in the hand while holding the breath, 

 provided the experimenter will catch only males, which are easily 

 recognized by their long antennae and their face-colors. Have 

 your correspondents been sure that they captured female wasps, 

 which alone have stings ? In the autumn the males are most 

 plentiful, and in that season one may easily show an astonished 

 companion how safely a wasp can be handled while holding one's 

 breath, and afterwards while breathing also ; but in doing this, I 

 always take care to catch the right kind of wasp first. My faith 

 in the supposed safeguard has never been sufficient to try the ex- 

 periment intentionally with female Aculeata. Will not Mr. Safford 

 make the test in the spring, and report his results once more ? He 

 will then doubtless agree with Life, that the most important thing 

 in holding a wasp is how to let go. W. M. D. 



Cambridge, Mass., Jan. 20. 



