SCIENCE. 



3i 



of disease in the higher plants, for they germinate and 

 grow under the usual conditions of our summer weather, 

 and penetrate and develope in and at the expense of 

 otherwise healthy plants. Under these conditions it is 

 only necessary to place the matured spores on the parts 

 of the plants inhahited by the fungus to ensure its 

 growth, and, in consequence, the disease. It is, how- 

 ever, even in these cases, evident that much must de- 

 pend upon the peculiarities of the weather, etc., whether 

 the host or the parasite is specially favored or repressed, 

 and so whether or not the disease is seriously injurious. 



Rust spores on young wheat leaves in spring time are 

 as certain to germinate and penetrate the tissues as 

 arsenic is to poison mammals. In this case development 

 goes on but slowly however, unless specially favorable 

 conditions occur for the parasite, when, in the latter case, 

 it makes its presence easily recognized by the disastrous 

 results too often witnessed. Smut in wheat is less af- 

 fected by peculiar states of the climate. The spores send 

 their germinal tubes into the tissues of the seedling 

 plants ; the fungus grows with the host, and finally, just 

 before harvest time, matures its spores again in the 

 aborted wheat grains. Blight-bacteria, again, need only 

 to be introduced in few numbers into the living bark cells 

 ot a healthy pear tree, during ordinary Summer weather, 

 to insure their reproduction and multiplication in myriad 

 numbers, and the death of the invaded cells in conse- 

 quence of their deleterious action. It is by on means 

 true that plants must be in an enfeebled condition that 

 such parasites may grow upon them. The very vigor of 

 the host often adds, by furnishing more assimilable food, 

 to the extreme development of the parasites. 



On the other hand there are many fungi that only grow 

 on the higher plants when these have been injuriously 

 affected by something else, or when the conditions are 

 peculiar and altogether unfavorable for their proper de- 

 velopment or growth. Thus apples become "scabby" 

 by a fungus belonging to the preceding class, but they 

 often rot while hanging on the trees through the effects of 

 other fungus never injurious to perfectly sound fruit with 

 an unbroken skin or epidermis. Peaches rot upon the trees 

 under the effect of a mould-like fungus which produces 

 myriads of spores that readily float like dust in a dry 

 atmosphere, but these do not germinate except in mois- 

 ture, and, as their duration of vitality is very short, few 

 succeed in reproducing the plant except during rainy 

 weather, when one decaying peach may be a source of 

 contagion for hundreds of others. There are too great 

 numbers of leaf-dwelling fungi which only grow upon 

 these organs when from old age or other causes they have 

 lost their powers of existence through the diminution of 

 their vital forces, so that the mycologist learns to look 

 upon old and fading leaves for numerous specimens. In 

 the descending scale we find vast numbers of still other 

 fungi which only grow upon really dead organic matter ; 

 these however have no share in the title parasitic. 



It may therefore be concluded that, in the struggle for 

 existence, many species of fungi have acquired the physi- 

 ological power of overcoming the defensive forces of cer- 

 tain higher plants in a state of health under ordinary con- 

 ditions of plant life and growth, while others, truly para- 

 sitic in their nature, are obliged to seize upon favorable 

 chances to take advantage of slight or serious misfor- 

 tunes happening to their hosts, thus giving the kick to 

 one already going down hill. 



I have thus endeavored to point out some of the general 

 truths of vegetable pathology as they appear to one who 

 accounts himself a student but not a master of the subject. 

 I enter the open gateway of a great field, and make little 

 incursions here and there, gathering now and again from 

 the abundance offered, material for many odd hours of 

 microscopical work, which again furnishes " food for 

 thought " when the lamp has been extinguished and the 

 scalpels laid away. There is much room for many better 

 workers, and much interest for those who will work. 



CROTON WATER OF NEW YORK. 



It is" admitted on all sides that an improved supply of 

 water for New York city, both in regard to quantity and 

 quality is imperatively demanded by its citizens, and the 

 subject, in one form, will shortly be discussed by the legis- 

 lature at Albany. 



In regard to quantity, the solution appears a simple 

 one, as the present supply is adequate for all legitimate 

 purposes ; in fact, if it were not for the great waste of 

 water now practised, the supply would exceed all de- 

 mands of the present population. 



It is claimed by the "Sanitary Engineer" that this 

 waste is due to imperfect plumbing, and the facts and 

 figures given, show that such a supposition is, in part, 

 correct. Every householder, however, knows that a 

 wasteful use of the water, due to the whole supply of 

 the city being at the command of every individual, must 

 lie at the root of the evil. 



Much printers ink has been wasted in printing procla- 

 mations from the authorities to the people, counselling 

 economy in the use of the water, but the time has, per- 

 haps, now arrived when the legislature should decide to 

 employ some remedy and make radical changes in the 

 method of distributing the supply. 



The method of running the main supply direct into 

 every house, is certainly the most primitive and least sci- 

 entific or practical of all means at command. It is an 

 invhation for waste and extravagance, and has proved an 

 utter failure, as the means for thus distributing a supply 

 are so defective that, while one family in a house can 

 draw on the Croton river at will, others, less fortunate, 

 on another level endure a constant water famine. 



The whole evil of this imperfect distribution of the water 

 could be remedied, if the supply were made by cisterns 

 only. This system has always been in use in London 

 and answers admirably. Every householder under this 

 system has one or more cisterns filled twice daily, and 

 is not restricted either to the number, capacity or location 

 of the cisterns. Thus each householder pays prorata 

 for the actual amount of water he consumes annually, 

 which, beyond doubt, is the only equitable method of 

 charging a water rate. In the case of manufacturers a 

 meter is substituted, if desired. 



A natural accompaniment of this system is a universal 

 high pressure of water throughout the city, which pro- 

 vides that cisterns in the highest part of every house shall 

 receive its supply daily. This mitigates the evil under 

 the present system, of pumping and carrying water above 

 the first and second stories, now necessary in most 

 houses in New York city. 



The economy of the cistern system is self evident for 

 no one would call for more water than he could legit- 

 imately use and increase the annua! water tax. Thus 

 a premium for economy rather than waste is offered. In 

 a sanitary point of view many advantages are attached to 

 the use of cisterns, as the large amount of impurities have 

 time to subside and the water is consumed in an improved 

 condition. It is usual to construct one of the cisterns 

 with slate, which is reserved for drinking purposes. 



The plea that such a system curtails the proper use of 

 water has no foundation in fact. The writer lived in a 

 house in London for many years, under this system of 

 supplying water, and found he received not only abund- 

 ance for family use, but sufficient to water a large gar- 

 den. If the system here described were put in practice in 

 New York city, and the plumbing perfected, the present 

 supply of water would be found ample, and part of the 

 money now proposed to be wasted in making new stor- 

 age reservoirs might be profitably used in building pump- 

 ing stations, which would give a high pressure of water 

 to all the upper rooms in the city, and increase the effic- 

 iency of the means now at command for extinguishing 

 fires. 



