Jtme 13, 1878] 



NATURE 



173 



jar, two strips of tin, to which the circuit wires were 

 attached. When the simple instrument was used as a 

 transmitter, articulate sounds were heard very loud and 

 distinct in the distant telephone, though occasionally 

 marred by what appeared to be the rattling of the cinders 

 in the jar. With this transmitter sounds were also quite 

 audible, even when the speaker stood several yards away 

 from it. 



I next took a shallow box, made of thin wood, about 

 fifteen inches by nine inches, and filled it with cinders, 

 taking care, in the first place, to nail to the inside of its 

 ends two pieces of tin to which wires could be attached. 

 Having nailed down the thin lid of the box, and included 

 it in the circuit of the telephone, along with one Leclanche 

 cell, I found that it made both a very sensitive micro- 

 phone, as well as an excelleiit transmitter for the ordinary 

 telephone. With three of these boxes hung up like 

 pictures on the walls of a room, and connected in circuit, 

 almost any kind of noise made in any part of the room 

 was revealed in the telephone. Speaking was heard 

 distinctly, and a part-song by two voices in the middle of 

 the floor was rendered with surprising clearness and 

 accuracy. 



In my next experiment, still using the same cell in the 

 circuit of the telephone, I tried as transmitter a single 

 elongated cinder with the wires Avound tightly round each 

 end. Sounds uttered close to this cinder were quite 

 audible, but I failed to hear them when I substituted for 

 the cinder the carbon of a Bunsen cell with brass clamps 

 firmly attached to each end, into which the circuit wires 

 were screwed. Possibly either the more porous and 

 friable nature of the cinder or the comparative looseness 

 of the wire attachments, may have had something to do 

 with this difference of effect. 



I next removed the Leclanche cell from the circuit and 

 used as transmitter the jelly can containing dry cinders. 

 I sometimes fancied that I heard sounds even with the 

 cinders dry, but they became faintly, though distinctly, 

 audible when the cinders became slightly moistened by 

 the breath of the speaker. However, on pouring water 

 into the jar, so as almost to cover the cinders, the sound 

 was heard on the telephone almost as well as when the 

 Leclanchfe cell was in circuit. I did not, however, hear 

 any sound with the cinders removed and water only in 

 the jar, not even when the conducting power of the water 

 was increased by being slightly acidulated. 



In my next experiment I tried if the jar with the 

 cinders would act as a receiver as well as transmitter, 

 and was not a little surprised to find that it did so. For 

 this purpose I used similar jelly cans, containing cinders 

 both for transmitter and receiver, and included a battery 

 of two Grove's cells in the circuit. Articulate sounds 

 uttered in the one cinder jar were distinctly heard in the 

 other, and even voices could be distinguished. How- 

 ever, the results were not so good as I have no doubt they 

 will yet be, when better forms both of transmitter and 

 receiver are adopted. Here we have the beginning of a 

 kind of telephone worked entirely by the electric current 

 without the aid of magnetism. I also tried successfully 

 an ordinary telephone as transmitter and a cinder jar 

 as receiver, but in this case, the sounds were some- 

 what fainter and not so easily distinguished. I re- 

 marked, also, that when an intermittent current was 

 sent through^ the cinder jar, a very distinct rattling noise 

 issued from it. 



In order to find out if the cinders in the receiving jar 

 were atall jostled about when sounds were beingtransmitted 

 to it from a similar jar, the following experiment was 

 tried. A strong battery was included in the circuit, and 

 a clean glass jar containing cinders taken as receiv- 

 ing instrument. When this was taken into a dark 

 room small flashes of electric light were observed 

 here and there amongst the cinders while sounds were 

 being sent. James Blyth 



RESTING SPORES 



A VERY interesting memoir by Dr. Wittrock, the 

 ■^~^ well-known Swedish botanist, was communicated 

 to the Swedish Academy of Sciences in December last 

 " On the Spore-Formation of the Mesocarpeas and 

 especially of the New Genus Gonatonema." The chief 

 interest of this memoir seems to us to He in its somewhat 

 novel interpretation of some pretty well-known physio- 

 logical facts, which we shall as briefly as possible proceed 

 to enumerate. 



In one lovely group of green-coloured algae we find a 

 number of very pretty species, many of which consist of 

 one-celled forms, and others of which, obeying a law 

 of cell growth, not only produce new cells but also 

 cause these to adhere to one another and so, as this 

 growth goes on, give a chain-like or filamentous appear- 

 ance to the mass. These filamentous green freshwater 

 alga^ are very common. Dillwyn, in the beginning of 

 this century, knew and described many of them, and he also 

 seems to have well known that the contents of some of 

 their cells formed oval bodies called resting spores. The 

 merit of having worked out the history of these spores 

 belongs to Prof. A. de Bary, from whose researches it 

 was first made clear that in some of these forms (Zygnema) 

 one of the chains of cells will come to lie alongside of 

 another chain, and then the cell- wall of two opposite cells 

 will grow outwards until they meet. On meeting the; 

 tips of these outgrowths will be absorbed, and the two 

 cells will thus communicate by means of this newly- 

 formed canal, whereupon it will follow that the contents 

 of both cells will each go half way to meet the other, and 

 their conjoining will take place in the newly-formed 

 canal, or sometimes in one of the cells ; or that the whole 

 of the contents of one of the cells will pass over and com- 

 bine themselves with the contents of the other. In either 

 case the result will be the formation of a new body— well 

 known as the zygospore, but also known under many 

 other denominations. But, again, in other forms 

 (Mesocarpus), while the initial process will be the 

 same so far as the formation of the cross channel 

 goes, the further steps differ much, it being only 

 the green-coloured portions of the protoplasm of 

 both cells that move over into the canal, whereupon 

 the central portion of this green mass, composed of 

 about equal parts of the contents of the two cells becomes 

 developed into a zygospore, leaving the rest of the cell- 

 contents to fade away. The physiological import of these 

 two quite different phenomena was therefore this : in 

 Zygnema and its allies the total contents of two of the cells 

 were required to form a zygospore — whereas in Mesocarpus 

 this was formed out of only portions of the cell-contents. 

 There is thus no strict analogy between these two forms of 

 zygospores, and they probably should not both receive the 

 same name. De Bary perceiving this, referred to the one 

 as resting-spores formed by the partition of the zygospore 

 [the parts destitute of green contents having been par- 

 titioned oftj, strangely applying this term to that stage 

 when the two cells had combined to form one, and to the 

 other as resting-spores without partition. De Bary's 

 attempt at being logical has apparently been overlooked 

 by many writers on this subject, notably by such eminent 

 investigators as Max Cornu and Sachs, who still apply the 

 term zygospore to both forms, but Pringsheim has grappled 

 with the difficulty in his most thoughtful paper " On the 

 Alternation of Generation in Thallophytes," and suggests 

 that the first stage in the reproductive process in Meso- 

 carpus is the ^' conjugation "-stage — here the cells join 

 and become, so far as their cell-walls are concerned, 

 united into one. The next stage is the more important 

 one, in which the cell-contents commingle, and the result 

 is the production of the central cell — a carpospore — 

 and of two or four cells which surround it, and 

 form the equivalent of a fruit-like body, or sporocarp, 



