THE AMEKICAN MONTHLY 



[January, 



section across the length of the 

 filament would show that the cells 

 have a triangular shape, and if we 

 look at the filament in any position, 

 we will observe that it is twisted. 

 In this condition the plant is doubt- 

 less well known to most collectors ; 

 but it is not so usual to find it 

 fruiting. During the month of 

 September w^e obtained some excel- 

 lent specimens with well-formed 

 zygospores. The appearance of 

 the fruiting plant is shown in our 

 Fig. 7. This beautiful plant can 

 be easily grown in confinement, and 

 its process of growth and conjuga- 

 tion carefully studied without the 

 necessity of visiting its native pond 

 a second time. We have now some 

 perfectly healthy specimens of D. 

 ISwartzii, which were collected last 

 September. In fact, the same is 

 true of most Algas, even the most 

 delicate. We will give some hints 

 about growing Algfse in aquaria, in 

 a future number of the Journal. 



A Method of Making Sections 



of Insects and tlieir 



Appendages. 



BY J. D. HYATT, EX OFFICIO F.E.M.S.^ 



In studying insect anatomy it is 

 frequently necessary to make a sec- 

 tion through a part of the body, 

 or through some organ which con- 

 sists of several pieces, in such a 

 manner that the section will show 

 all the parts in their normal position. 

 How 10 make such a section 

 through hard, chitinous organs, 

 such as stings and ovipositors, 

 sufficiently thin to allow of exami- 

 nation by transmitted light, and at 

 the same time retain all the parts 

 in place, was a problem that, for 

 several years, defied all my at- 

 tempts to solve by any process on 



*President of the N. Y. Microscopical 

 Society. 



record. After many fruitless at- 

 tempts by other devices of my 

 own, the following very simple 

 method has proved entirely suc- 

 cessful. 



The insect, or organ, is placed in 

 alcohol until it is thoroughly per- 

 meated by that fiuid, and then 

 removed to a clear, alcoholic solu- 

 tion of shellac, in which it may re- 

 main for a day or two. 



Fit a cylinder of soft wood into 

 the well of the section-cutter ; 

 split this cylinder through the mid- 

 dle, and cut a groove in one or 

 both of the half -cylinders, sufficient- 

 ly large to admit the object with- 

 out pressure ; put the two pieces 

 together with plenty of thick shel- 

 lac, and tie them with a thread. 

 When the shellac is quite hard, 

 which will be the case in a day or 

 two, place the cylinder in the sec- 

 tion-cutter, and after soaking the 

 wood with warm water, sections 

 the -g-J-g- of an inch in thickness, 

 or less, may readily be made. 



Should the shellac prove so 

 opaque as to interfere with a 

 proper examination, a drop of 

 borax solution will immediately 

 remove this difficulty. 



New Microscopes and Acces- 

 sories. 



I. 



The latest design for a stand is 

 the one which we illustrate on the 

 opposite page. The stand here 

 shown is made by Messrs. Sidle 

 & Poalk, of Philadelphia, who 

 have recently gone into the busi- 

 ness of manufacturing microscopes 

 and objectives. 



The cut is so clear that but few 

 words of explanation are necessary. 

 The aim of the makers seems to 

 have been to produce a good, cheap 

 stand, which would be adapted to 

 all kinds of work. For ordinary 



