DR. THOMPSON, ON PULMONARY CONSUMPTION. 227 



Cycadeaj, whether the above-mentioned cellular body in the interior of the 

 pollen is common to all the plants of these families ; and whether the 

 terminal cell of this body is intended in all cases to serve the same pur- 

 poses as in Pinus sylvestris. If it be so, a new and important characteristic 

 of these families U'ill have been obtained. The examination of the pollen 

 should, however, be made only whilst it is fresh ; after it has become 

 dry, the fissure to which I have referred may still be seen, but not the 

 cellular body. Geleznoff's careful observations on the impregnation of the 

 Larch deserve to be carefully repeated. 



If, as may confidently be expected, the appearances which have been 

 here described are found to occur in all the Coniferfc and Cycadete, the 

 reproductive organs and the formation of the embryo of these plants will 

 differ from those of all other phanerogams in the three following essential 

 particulars. 



1. The Coniferaj and Cycadeae have naked ovules, that is to say, their 

 ovules originate in an open fruit-scale, whilst in all other (phanerogamous) 

 plants they make their appearance in the interior of a special organ, that 

 is in the hollow of the ovary. 



2. The embryo-sac of the Coniferaj and Cycadea; jjroduces corpuscula, 

 which are large cells of the albumen, varying in number, and situated at 

 the apex of the embryo-sac, into which the pollen-tube enters, in order 

 that after having extended itself within the coiyusculum, it may form the 

 first cells of the embryo. In all other plants the corpuscula are wanting, 

 the pollen-tube simply enters into the embryo-sac, and forms therein the 

 first cells of the embryo. 



3. The pollen-tube of the Coniferai and Cycadeae is not (as is the case 

 in other phanerogams) a prolongation of the inner true pollen-cell, but an 

 extension of the terminal cell of a small body consisting of several cells, 

 which body originates in the interior of the pollen-cell, the contents of 

 which it appropriates to the purposes of its own development. 



This work is now more than ever one that we can recom- 

 mend to the botanical student, as an introduction to the use 

 of the microscope. 



Lettsomian Lectures on PaLMo^fARY Consumptiok. By Theophilus 

 Thompson, M.D., F.R.S. London. Highley. 



This work consists of three lectures devoted to the subject of 

 pulmonary consumption and its treatment. In the first lec- 

 ture there are some very good remarks on the microscopic 

 appearances afforded during the progress of tuberculous 

 disease of the lungs. It has oftentimes been denied that the 

 microscope is of any value in the diagnosis of tubercle ; and 

 on this subject we subjoin the remarks of Dr. Thompson, 

 whose opinion no one will doubt is that of a thoroughly 

 practical man : — 



As respects the progress of consumption, the principal appearances of 

 the expectoration may be described under three divisions : — 



1. Frothy ; characterising irritation, which, however, may be produced 

 by various causes, besides the presence of tubercular deposit in the 

 cells. 



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