1882.] 



MICKOSCOPICAL JOUKNAL. 



37 



experiment only (No. 2), out of the 

 thirteen was wholly in favor of the 

 theory, and that lasted only twenty- 

 three days. Still six per cent, more of 

 the infected plants took the Uredo 

 than of the uninfected. This is a 

 very small portion, far too small in 

 my humble opinion to constitute con- 

 vincing evidence. I believe, however, 

 that it can be accounted for by my 

 own negligence in not thoroughly 

 cleaning the bell-glasses before using 

 them to cover fresh plants. Had the 

 last experiment (No. 13), however, 

 proved favorable to the theory I 

 should have regarded it as being much 

 more worthy of acceptation than I 

 can now do. It is only after much 

 patient work and careful considera- 

 tion that I felt myself bound to differ 

 from the eminent botanists abroad 

 who do not accept the heteroecism of 

 Puccinia graminis as established be- 

 yond question. 



There are two other experiments 

 not included in the thirteen which 

 were performed by me that I think 

 worthy of notice. 



Experiment No. 36. — On the 2d 

 August one oat plant with ten leaves 

 upon it was inoculated with yEadium 

 berberidis spores. A very large quan- 

 tity of ripe y£ddium spores was used 

 — on the fifteenth day Uredo appear- 

 ed upon the oat plant. On the 9th 

 September (38th day), these Uredo 

 spores were examined and found to 

 be the Uredo of Puccinia coroftata, 

 Corda. Now had this experiment 

 been carelessly performed the infer- 

 ence would have been that the yEci- 

 dium spores had produced the Uredo 

 of P. graminis. 



Experiment No. 40. — Six wheat 

 plants were infected with the spores 

 of Uredo linearis at 4 p. m. on the 

 13th August. On the 24th they all 

 were simultaneously affected with 

 Uredo, showing that the Uredo had 

 reproduced itself in eleven days. 



Our Histological and Pathologi- 

 cal Laboratories. 



II. 



In my previous article, published 

 in the December number of this 

 Journal, I attempted a fair exposi- 

 tion and criticism of the outfits and 

 manner of conducting the laborato- 

 ries in connection with medical 

 schools. My failing to clearly state 

 my opinion as to what should con- 

 stitute a good working laboratory, has 

 caused numerous inquiries. In order 

 to answer these and to bring the mat- 

 ter for discussion, I herein give 

 my views on the subject. 



First of all the room chosen should 

 be so situated as to eliminate any 

 possibility of tremor from outside 

 causes, and so constructed as to be 

 but slightly susceptible to motions 

 within. This is all-essential. That 

 it should be well lighted on all sides, 

 is a convenience but not a necessity. 

 What it lacks in natural light we can 

 supply, and artificial light is to be 

 preferred, owing to its steadiness. 

 The floor should be oiled thoroughly 

 and kept free from carpets or other 

 covering. The walls should be smooth 

 and of a dark color, thus preventing 

 any chance of cross rays by reflection. 

 Dark closet for storage, and chemi- 

 cals injured by light ; shelving for 

 stock-bottles and material in harden- 

 ing fluids ; sink with hot and cold 

 water ; several aquaria for frogs, sala- 

 manders, etc., are all needed. 



A cabinet containing various high- 

 power lenses, binocular eye-piece, 

 freezing microtomes and other appa- 

 ratus, occasionally needed for demon- 

 stration or inspection, is an impor- 

 tant addition. 



Each student must be provided 

 with a table, the particular style of 

 which is a matter of taste. I much 

 prefer Queen's revolving table, to 

 which has been added numerous lit- 

 tle drawers in which to keep cleaned 

 covers, slips, brushes, knives, needles, 

 and any small apparatus not in use. 



On each table should be a micro- 



