Between the gills of a mushroom

[rjlittlefield]

Today I noticed some mushrooms growing from some rotting roots at the edge of my lawn. I picked one, turned it over, and looked at its gills with the 10X magnifier that I always carry. Yep, black plates. Then I looked a bit closer and noticed what looked like some little dots down between the plates, where it's hard to see. I needed more light. So I held the thing up to the sun and got the light just right. Whoa!

Roughly speaking, and at much higher magnification, here's what I saw:



Here's a shot with more conventional lighting, after I ripped the thing open a bit.


These finger-like structures are amazingly fragile -- apparently little more than a thin membrane filled with water. They start to shrink as soon as they get exposed to the air.

In fact, to get the second shot, I had to switch lighting strategies away from my usual incandescents because the heat made the things dry out before I could shoot a stack! A Luxeon LED positioned an inch or so away from the subject worked better, but still I had to hurry before the dry air in the room dessicated the specimen.

I have little idea what the function of the fingers is. I can imagine they serve to maintain spacing between the gills, so the spores can drop out cleanly. Perhaps someone else knows for sure?

Hope you enjoy!

--Rik

Technical detail:

Image 1: 3.2X NA 0.10 objective on bellows & tubes, 55 frames at 0.0005" stacked with Helicon Focus, incandescent lighting from behind. Slight crop.

Image 2: 16mm Luminar at f/3.5 (aperture setting 2) on bellows & tubes, 17 frames at 0.001" stacked with Helicon Focus, Luxeon LED from the side. Full frame.

[S. Alden]

Both images are great and I do not have a "best one". I like them both. Nice details and now I will have to go out and pick mushrooms

I have to admit. I never got the hang of helicon focus.

[rjlittlefield]

I checked with a friend who knows about these things.

He pointed me to this link: http://www.ilmyco.gen.chicago.il.us/Terms/cheil345.html.

The short summary is that:
1. The finger-like structures are called cystidia (sing. cystidium)
2. They are well known and are diagnostic of the species, but
3. He doesn't know what their function is, either.

I love biology -- it's so easy to find questions and so hard to find answers!

--Rik

[Ken Ramos]

I really like these Rik. It is amazing that you could capture the spores or what I believe are spores by the millions. In the study of myxomycetes the spores are so small that a magnification of 400 to 1000X is prefered and actually to make a species id of the myxo from the spores one has to use a 100X oil immersion objective most of the time.

These are some great shots and like you I wonder what the purpose of the water filled fingers are unless they are there to act as a reserve of moisture for the fungi. The contrast and sharpness of the two images is extremely nice. Some very nice shots indeed there Rik.

Sue said:

Nice details and now I will have to go out and pick mushrooms

Be cautious of the "shrooms" you pick Sue. I think the days of black lights and old Pink Floyd albums have passed. Besides I think they make you sick initially from what I have read, kind'a like pyote buttons.

[rjlittlefield]

Ken, that Luminar at f/3.5 is essentially a very high quality microscope objective that's diffraction-limited at NA 0.14, has essentially zero CA, and shows no change in image quality across the frame. All of this is just great for stacking. In terms of resolution, it's down by a factor of 10 from good oil immersion objectives, but on the other hand it's only a factor of 10. In this case, that means there's not nearly enough resolution to tell much about the shape of the spores, but plenty to tell that they come in little blocks of 4. The picture below is from a single frame (unstacked), at the lower left of the composite I posted earlier.

I have to say, by the way, that my personal favorite is the first picture. Somehow with that backlighting and the row-after-row-after-row pattern, it feels like I'm peering into the windows of some strange multistory building after dark...but nothing makes sense. Very surreal! The second one feels to me like, well, a nice piece of technical documentation.

--Rik

[Ken Ramos]

Quite interesting Rik. I have a few old objectives from a student microscope lying around here somewhere. I may try and see if I can get one of them to work one of my Sony cameras.

[rjlittlefield]

I have a few old objectives from a student microscope lying around here somewhere. I may try and see if I can get one of them to work one of my Sony cameras.

It's pretty easy with an SLR -- you just stick the objective on the end of a bellows & pretend that it's a macro lens with a fixed aperture.

But with a point-and-shoot, I don't think you'll be able to make it work with just the objective. You need a relay lens to refocus the light from the objective so that it goes through the camera's entrance pupil. Such lenses are commonly available, of course...they're called "eyepieces" and you use them by, uh, hhmm...you know a lot more about that than I do!

Essentially, all I'm doing is plopping the DSLR's sensor right in the image plane of the objective, the place that the eyepiece would normally be focused on. The only real advantage is that I'm not tied to a microscope body, so I can look at small parts of big things without much trouble.

--Rik

[Ken Ramos]

Yeah I just found out that it doesn't work all that well with any fixed lens system, even the small ones. But it gave me something to play with for a little while. I guess the Axiostar and the Meiji stereo will just have to suffice.