iS83.] 



MICROSCOPICAL JOURNAL. 



51 



in the appearance of the corpuscles. 

 They become granuhir, and some of 

 them undergo slow changes of form, 

 budding, etc., as Dr. Heitzmann has 

 described in his book, recently pub- 

 lished. When the corpuscles begin to 

 become granular, there is a time when 

 they present an appearance of reticu- 

 lation. But careful observation with 

 high-powers fails to show any connect- 

 ing net-work. There is nothing but 

 a breaking up of the contents into sep- 

 arate granules ; and as the action of 

 the reagent continues the granules be- 

 come more distinct, until they can be 

 verv clearly defined bv a good objec- 

 tive. I have such a preparation to 

 show you this evening. 



It is not convenient to show a white 

 corpuscle of the blood this evening, 

 but a pus-corpuscle will serve us just 

 as well. It is asserted that the retic- 

 ulum can be seen in these corpuscles 

 without any preliminary treatment 

 with reagents. The true appearance 

 ol" a white corpuscle is like a color- 

 less, transparent disc, distinctly gran- 

 ular, but there is no net-work about 

 it. 



The Amxba consists of a simple 

 mass of protoplasm, containing gran- 

 ules. Under a very high power very 

 minute granules can be detected in 

 the clearest portions of the amoeba's 

 substance. But there is no reticulum 

 whatever to be seen. I hope to be 

 able to show you an amoeba this even- 

 ing, so that you may judge for your- 

 selves whether it is granular or 

 reticulated. 



It has been suggested that Dr. 

 Heitzmann may show an appearance 

 of a reticulum where no reticulum 

 exists. It should always be con- 

 sidered that errors of interpretation 

 are very easily made in microscopical 

 work. Sometimes it is not possible 

 to interpret the image in the micro- 

 scope with any degree of certainty. 

 In this case, however, there need be 

 no uncertainty. The Amoeba or the 

 blood-corpuscles do not introduce 

 these sources of error. What thev 

 may be made to show under special 



conditions of illumination and wrong 

 adjustment of the objective, must re- 

 main a matter of conjecture until Dr. 

 Heitzmann demonstrates what he has 

 seen so that all in this audience may 

 see it. It appears, therefore, from 

 what has been said, that the net-work 

 is described in granular structures 

 only. It is seen in white blood-cells, 

 which are granular, in the Amceba, 

 which is granular, but not in the red 

 blood-corpuscles until after they are 

 made granular by the action of chemi- 

 cals. 



It is a fact well known to observers 

 with the microscope, that any body 

 regularly marked with fine and close 

 dots, can be made to appear as though 

 covered with fine, continuous lines. 

 The dots merge into each other, and 

 form lines in the image. Thus, in the 

 diatom Pleurosigtna afigulatiun, an in- 

 ferior objective will show the mark- 

 ings as fine, distinct lines, but a better 

 lens will resolve the lines into rows 

 of dots, a fact familiar to every micro- 

 scopist. It is doubtless owing to this, 

 that the granular structure of proto- 

 plasm has been taken for a reticulum, 

 but I cannot for a moment regard 

 such an error of interpretation, which 

 is still persisted in beyond all reason, 

 as pardonable in a person of experi- 

 ence. It is a fact that there is not a 

 microscopist of authority in the coun- 

 try who has been able to see the 

 reticulum described by Dr. Heitz- 

 mann. W'ithout an exception, all who 

 have looked for it have declared their 

 failure to find it, although following 

 Dr. Heitzmann's instructions in every 

 particular. 



I believe the strongest, and the 

 most convincing argument against this 

 bioplasson doctrine, is the fact that 

 the reticulum which these gentlemen 

 declare is so readily observed, has 

 hitherto entirely escaped the notice of 

 the best histologists in the world. 

 Dr. Heitzmann has used these words : 

 "Take a drop of pus, fresh, without 

 adding anything, and you will see the 

 wonderful structure in each pus-cor- 

 puscle with great ease." 



