1356 



Journal of Applied Microscopy 



Demonstration of Reticu- 

 late Vessels. — The teacher of 

 plant histology is usually seek- 

 ing for the best possible mater- 

 ials to illustrate the several 

 kinds of cells that are to be 

 examined by his students. For 

 well defined reticulate vessels, I 

 have seen nothing to equal those 

 found in the thickened roots of 

 Arenaria striata, which grew in 

 our botanic garden. They are 

 somewhat different from those 

 found in the stems of Impaficfis. 

 W. J. Beal. 



In the cuts of starchy gran- 

 ules of the pea, they are repre- 

 sented as having cracks, or checks in the middle. I wonder if it is generally 

 known that the checks seldom appear if the peas are placed in alcohol or glycerin 

 before drying ? W. J. Beal. 



QUESTION BOX. 



Inquiries will be printed in this department from any inquirer. 

 The replies will appear as received. 



5. Will you kindly refer me to a good method of how to make a biologic 

 aquarium ? In the Journal of Applied Microscopy are a few notes on Culti- 

 vation of Algae, but not sufficient for an amateur. What should be the soil- 

 gravel, sand, or mud from a pond ? How proceed to stock it and with what ? Is 

 the evaporation to be supplied from a pond or hydrant ? If glass cover on, can 

 there be enough air to pass between for living ? I am desirous of having a 

 number of jars for general elementary biology work ; to supply Amoeba, Hydra 

 Chara, Vorticella, Spirogyra, Vaucheria, Nitella, Vallisneria, etc. — v. a. l. 



6. What is Scott's method for the examination of blood ? — t. g. s. 



7. Can tinted paper be used for the haemoglobin test ?^ — t. g. s. 



REPLY TO QUESTIONS 3 AND 4 IN THE MAY NUMBER. 



The Welsbach light is practically worthless for high-power microscopy, either 

 visual or photographic, for with condenser focused, as it should be, an image of 

 the fabric of the mantle is projected into field of view. Have found no difficulty 

 in making photographs up to Xl'-^OO, using H. I. objectives and Huyghenian 

 oculars, with oil lamp, half-inch wick. Render rays approximately parallel with 

 bulls-eye, or better, a large size, short focus photographic lens placed at its focal 

 distance from lamp flame, and converge on object with substage condenser 

 sharply focused, achromatic condenser decidedly preferable, but Abbe con- 

 denser will answer fairly if nothing better is available. No noticeable advantage 

 derived from the use of achromatic, periscopic, orthoscopic, or compensation 

 oculars over the Huyghenian, when used with achromatic objectives. — f. j. k. 



